1ST TERM SS1 CHEMISTRY SCHEME OF WORK AND NOTE

FIRST TERM E-LEARNING NOTE

SUBJECT: CHEMISTRY  CLASS: SS1

SCHEME OF WORK

WEEK TOPIC

1. INTRODUCTION TO CHEMISTRY
2. LABORATORY FAMILIARIZATION
3. NATURE OF MATTER
4. ELEMENTS & SYMBOLS, VALENCY
5. COMPOUNDS AND MIXTURES
6. STANDARD SEPARATION TECHNIQUES FOR MIXTURES
7. PARTICULATE NATURE OF MATTER
8. IUPAC NOMENCLATURE OF CHEMICAL COMPOUNDS
9. ATOMIC NUMBER, MASS NUMBER, ISOTOPES AND CALCULATIONS
   1. STRUCTURE OF THE ATOM: ORBITALS AND ELECTRONIC

      STRUCTURE OF THE ATOM

      Also Read:

      • 1ST TERM SS1 AGRICULTURAL SCIENCE SCHEME OF WORK AND NOTE
      • 1ST TERM SS1 BIOLOGY SCHEME OF WORK AND NOTE
   1. REVISION
   2. EXAMINATION

       

      REFERENCE MATERIALS
      

• New School Chemistry for Senior Secondary School by Osei Yaw A.
• Practical Chemistry for Schools and Colleges by G. O. Ojokuku
• Calculation in Chemistry by E.U. Akusoba and G.O Ewelukwa
• WASSCE Past Questions and Answers on Chemistry
• UTME Past Questions and Answers on Chemistry

WEEK ONE

TOPIC: INTRODUCTION TO CHEMISTRY

CONTENT

• CHEMISTRY AS A SCIENCE SUBJECT
• BRANCHES OF CHEMISTRY
• SOME LABORATORY APPARATUSES AND THEIR USES

CHEMISTRY AS A SCIENCE SUBJECT

Science is an organized body of knowledge gathered through systematic experimentations and philosophical observations. Chemistry can be defined as a branch of science which deals with the study of the nature, structure, composition, properties and uses of all forms of matter and the changes in structure and composition which matter undergoes.

BRANCHES OF CHEMISTRY

Chemistry is divided into three main branches, namely

Physical chemistry

Organic chemistry

Inorganic chemistry

Physical chemistry deals with the physical aspect of chemistry like quantum theory, heat and electricity.

Organic chemistry deals with the study of carbon and its compounds.

Inorganic chemistry deals with the study of elements, their properties and uses

SCIENTIFIC METHODS OF DISCOVERIES

Scientific method of discovery includes the following steps and stages:

1. Observation
2. Pattern
3. Problem
4. Hypothesis,
5. Experiments
6. Theory
7. Law

Hypothesis refers to a prediction or guesses which explains an observed problem. When the hypothesis has been tested and found to be true within the limits of available evidence, it becomes a theory. A theory which has been extensively tested and proven correct without any exception becomes a scientific law.

EVALUATION

1. Define chemistry
2. State the stages or steps involved in scientific discoveries
3. When does a theory become a scientific law?

    

APPLICATIONS OF CHEMISTRY

Chemistry is applied in our everyday life as different activities take place in the environment. The effect of chemistry is felt in different aspects of life such as cooking, washing with soaps or detergent, digestion of food, drugs etc. Other applications of chemistry include health care, transportation, food, houses and clothes.

CAREER PROSPECTS IN CHEMISTRY

Chemistry is involved in our everyday lives and there is a vast range of careers open to those who have studied chemistry at any level. Great career opportunities exist both inside and outside the laboratory. You can choose a career from different fields such as:

1. Pharmaceutical/drug development
2. Science education
3. Chemical engineering
4. Mining and Metallurgy
5. Pure and applied chemistry
6. Petroleum and Petrochemical Engineering
7. Quality control
8. Medicine and surgery
9. Chemical analysis/forensic science
10. Environmental Chemistry
11. Science Laboratory Technology
12. Biochemistry etc

     

EVALUATION

1. State five applications of chemistry in our daily life.
2. Mention five adverse effects of chemicals and how they can be controlled.

GENERAL EVALUATION

1. Mention ten (10) career opportunities in chemistry.
2. List the branches of chemistry.

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio. Pg 2 to 7
• Practical Chemistry for School and Collegs by G. O. Ojokuku pg 2-15

WEEKEND ASSIGNMENT

1. The aspect of chemistry that deals with the study of carbon and its compound is called (a) physical chemistry (b) Organic chemistry (c) Inorganic chemistry (d) Analytical chemistry
2. Which of the following is not an adverse effect of chemistry? (a) pollution (b) poisoning (c) emulsion (d) corrosion
3. A stage in scientific method of discoveries is (a) Evaporating (b) Hypothesis (c) Dehydrating (d) dissolving
4. A theory which has been extensively tested and proven correct without any exception becomes (a) scientific law (b) hypothesis (c) experiment (d) pattern
5. Career prospects in chemistry includes all the following EXCEPT (a) Biochemistry (b) Quality control (c) Accounting (d) Metallurgy

THEORY

1. State five applications of chemistry in our daily life
2. Mention five laboratory apparatus and their uses

WEEK TWO

TOPIC: LABORATORY FAMILIARIZATION

CONTENT

• DEFINTION OF LABORATORY
• LABORATORY APPARATUS; MEANING, USES AND IDENTIFICATION
• LABORATORY SAFETY RULES

DEFINITION OF LABORATORY

A laboratory is a room or building equipped for scientific experimentation or research. It is a special facility where experiments are done and typically contains scientific equipment and apparatus.

LABORATORY APPARATUS

Laboratory apparatus refers to the various tools or equipment used by scientists working in the laboratory.

Some common laboratory apparatuses include: test tube, beaker, conical flask, flat bottomed flask, round-bottomed flask, funnel (plastic or glass) thistle funnel, brush, Woulff’s bottle tripod stand, retort stand, spatula, Bunsen burner, separating funnel, wire gauze, clamp, beehive shelf, gas jar, desiccated, reflux-condenser, Liebig condenser, pipette, burette, delivery tube, deflagrating spoon, u-tube, thermometer, aspirator bottle, wash bottle, chemical balance, reagent bottle, fume cupboard etc.

SOME LABORATORY APPARATUS AND THEIR USES

1. EVAPORATING DISH:
   

   It is made of porcelain. It may be round or flat bottomed. It is used in the evaporation of solution to dryness

2. BEAKER: It is available in different sizes. It is flat bottom cylindrical, graduated and usually with a lip for easy pouring of solution. It is used to hold solution or measure solution during an experiment.
3. ASPIRATOR BOTTLE: It is a Jerry can made of plastic or glass with a screw tap. It is used for storing distilled water during an experiment.
4. CRUCIBLE: It is usually made of porcelain with a lid to match. It can withstand high temperature hence, it is used for ignition of substances until they are decomposed.
5. WOULFF’S BOTTLE: It is a glass bottle used during the preparation of dry gases to hold liquid or solutions that are employed as drying agents or in absorbing unwanted gases.
6. CONICAL FLASK: It is commonly used during titration experiments. It is usually graduated and used to estimate the volume of a solution.
7. FLAT AND ROUND BOTTOM FLASKS: They are made of glass and are mainly used for boiling especially during distillation experiments.
8. STANDARD VOLUMETRIC FLASK: It has a flat-bottom, pear-shaped and with a narrow neck. It is used in preparing standard solutions to a specific or definite volume.
9. FUME CUPBOARD: It is usually a wooden cupboard with its front made of glass which can easily move up and down. It is used to prepare poisonous gases
10. DISTILLATION FLASK: It has a flat or round bottom with a slanting long side arm. It is used during distillation.
11. BELL JAR: It is made of thick glass, cylindrical, tall and usually with a knob at the top. It is used in combustion experiments.
12. GAS JAR: It is made of thick glass, cylindrical, tall and sealed at the bottom. It is used for the collection of gas over water or dry gas
13. DROPPING BOTTLE OR DROPPING PIPETTE: It is used in keeping or transferring solutions or reagents that are required in drops during experiments.
14. SPATULA: It is made of iron which looks like a spoon. It is used in transferring little quantity of solids into test tubes
15. BURETTE: It is used during titration experiments and also in transferring small volume of solution.
16. RETORT STAND WITH CLAMP: It is used as support during experiments
17. DESSICATOR: It is used in keeping and drying solids in an atmosphere that is dry and free of dust.
18. MEASURING CYLINDER: It is used to measure the volume of solutions.
19. KIPPS APPARATUS: It is used in the intermittent supply of gases.
20. WIRE GUAZE: It is used as a support for flasks during heating.
21. FILTER FUNNEL: It is used in filling the burette or in supporting the filter paper during filtration.
22. CONDENSER (LIEBIG): It is used in cooling or condensing vapour into liquid during distillation or when refluxing.
23. CENTRIFUGE: It is used in separating fine solid particles in a liquid.
24. TEST-TUBE: It is used in qualitative analyses to hold reactants’
25. SEPARATING FUNNEL: It is used in the separation of immiscible liquids.

EVALUATION

1. Mention ten (10) laboratory pieces of apparatus you know and their uses
2. Define (a) Laboratory (b) Laboratory apparatus

IDENTIFICATION OF SOME LABORATORY APPARATUS

Identify the laboratory apparatuses and laboratory set-up labeled A-I below:

LABORATORY SAFETY RULES

1. Dress well for the laboratory: Wear lab coat, safety goggles, footwear and tie long hair back to avoid catching fire
2. Keep pathways clear by placing items such as books and bags on the shelves or under the work table.
3. Do not taste or smell chemicals
4. Unauthorized experiments or procedures must not be attempted
5. Pay close attention to any cautions described in the laboratory exercise
6. Do not leave your assigned laboratory station without the permission of the teacher
7. Do not lean, hang over or sit on the laboratory tables
8. Fooling around or “horse play” in the laboratory is absolutely forbidden
9. Learn location of the fire extinguisher, eye wash station, first aid kit and safety shower.
10. Reports all accidents, injuries, and breakage of glass or equipment to instructor only.
11. Always follow the instructions given by your teachers
12. No eating or drinking in the laboratory at any time!
13. Leave your work station clean and in good order before leaving the laboratory

GENERAL EVALUATION

1. List ten safety measures in the laboratory
2. State the uses of: (a) Evaporating dish (b) Pipette (c) Retort stand (d) Measuring cylinder (e) Conical flask

READING ASSIGNMENT

• Practical Chemistry for School and Collegs by G. O. Ojokuku pg 2-15

WEEKEND ASSIGNMENT

1. An apparatus in the laboratory in which the preparation of poisonous gases is done is called (a) distillation tank (b) Aspirator bottle (c) fume cupboard (d) bell jar
2. In the laboratory _______ is used for the collection of a gas over water (a) gas jar (b) Woulff’s bottle (c) reagent bottle (d)burette
3. Two liquids which are immiscible with each other can be separated using (a) bell jar (b) gas jar (c) wash bottle (d) separating funnel
4. An apparatus used to hold drying agents during the preparation of dry gases is (a) conical flask (b) gas jar (c) Woulff’s bottle (d) flat bottom flask
5. Coloured reagent bottles are used to store reagents which are capable of _____ easily by sunlight (a) evaporating (b) decomposing (c) dehydrating (d) dissolving

THEORY

1. a.  Define Laboratory

   b.  List five safety measures that must be taken when in the laboratory

2. State the use of the following apparatuses
   1. Separating funnel
   2. Condenser

WEEK THREE

TOPIC: NATURE OF MATTER

CONTENT

• NATURE OF MATTER
• COMPARISON BETWEEN SOLID, LIQUID AND GAS
• TYPES OF CHANGE

NATURE OF MATTER

Matter is anything that has weight and occupies space. It exists in three states namely: solid, liquid and gas.

The fundamental difference between the three states of matter depends on the degree of movement of the particles they are made of.

SOLID STATE

The particles of a solid are tightly packed and held together by a strong electrostatic force.

The particles only vibrate to and fro about an equilibrium or a fixed position. They have a definite shape and volume and very difficult to compress.

LIQUID STATE

The forces of attraction between molecules of liquids are weak compared to that of solids. Hence they have slight movements. This is why liquids can flow. They have definite volume but not definite shape.

GASEOUS STATE

As a result of the distance between the molecules of gases, the cohesive forces between them are very negligible and so they move randomly. Gases have no definite shape and volume. They assume the shape of the containing vessel.

EVALUATION

1. What is matter?
2. List and explain the three states of matter.

COMPARISON BETWEEN SOLID, LIQUID AND GAS

SOLID LIQUID GAS

1.  Fixed mass Fixed mass Fixed mass

2.  Very dense Less dense Least dense

3.  Definite shape  Shapeless Shapeless

4.  Definite volume  Definite volume No volume

5.  Incompressible  Incompressible Compressible

6.  Particles vibrate  Particles vibrate, Particles move

 and move about  rotate and move about constantly

 a fixed position  about a restricted space  at a fixed speed.

EVALUATION

1. Define matter
2. Compare the three states of matter in terms of (a) density (b) compressibility

    

TYPES OF CHANGES  

Whenever a given substance is heated, its state changes. There are two types of changes: physical and chemical.

PHYSICAL CHANGE:

A physical change is a change which is easily reversible and in which no new substances are formed. Examples are:

1. Dissolution of common salt
2. Changes in states of matter such as melting of solids, freezing of liquids, evaporation of liquids, liquefaction of gases to solids, sublimation of solids.
3. Magnetization and demagnetization of iron nails.
4. Separation of mixture by evaporation, distillation, fractional distillation etc.

EVALUATION

1. What is a physical change?
2. Give two examples of a physical change.

CHEMICAL CHANGE:

A chemical change is a change which is not easily reversible and in which new substances are formed.

Examples of chemical change

1. Rusting of iron/metals.
2. Dissolution of metals and limestone in acids.
3. Fermentation and decay of substances.
4. Changes in electrochemical cells.
5. The addition of water to quick lime.
6. Burning of materials.

COMPARISON BETWEEN PHYSICAL AND CHEMICAL CHANGES

 Physical Change Chemical Change

1.  Easy to reverse  Difficult to reverse

2.  No new substances are New substances are always

 formed formed

3.  Very little energy changes There are often large heat

 take place  change.

4.  No change in mass The new substances formed have

different masses but the total mass is unchanged.

GENERAL EVALUATION/REVISION

1. What is a chemical change?
2. Give two examples of a chemical change.
3. State three differences between physical and chemical changes.
   
4. State the function of the following laboratory apparatuses: a) Fume cupboard b) Burette
   (c) Bunsen burner
   

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y. Ababio.Pg 8 -9

WEEKEND ASSIGNMENT

1. Which of the following changes is a chemical change? (a) melting of ice (b) liquefaction of air (c) slaking of lime (d) evaporation of a liquid
2. Which of the following substances will occupy a wider space? (a)carbon (iv) oxide (b) liquid milk (c) pieces of chalk (d) water
3. When a solid changes to gas directly, this process is called (a) freezing (b) sublimation

(c) vaporization (d) evaporation

1. Which of the following changes produces a new substance ?(a) reaction of water with sodium chloride (b) addition of acid to base (c) turning of margarine to oil (d) evaporation of water
2. Which one of the following has a fixed shape and volume?

(a) a cube of sugar (b) liquid wax (c) smoke (d) kerosene

THEORY

1. Give two differences between physical and chemical changes.
2. Give three processes, which involve a physical change

WEEK FOUR

TOPIC: ELEMENTS, SYMBOLS & VALENCY

CONTENT

• ELEMENTS AND SYMBOLS
• CLASSIFICATION OF ELEMENTS
• VALENCY
  

ELEMENTS AND SYMBOLS

An element is a substance which cannot be split into simpler units by ordinary chemical process. There are over one hundred known elements.

SYMBOLS OF ELEMENTS

There are three ways in which symbols of elements are derived.

1. From the first letter of the name of the element

   Element   Symbols

   Hydrogen H

   Oxygen O

   Iodine  I

   Fluorine F

   Nitrogen N

   Sulphur S

   Carbon  C

   Phosphorus P

2. The first letter written in capital letter and one other letter from its name written in small letter.

Element Symbol

Chlorine Cl

Bramine Br

Calcium Ca

Aluminium Al

Magnesium Mg

Berylium Be

Helium  He

Neon  Ne

Lithium L

1. The symbols of some elements were derived from their Latin names.

Elements  Latin name Symbols

Mercury  Hydragyrium Hg

Sodium Natrium Na

Iron Ferrum Fe

Copper Cuprum Cu

Silver Argentum Ag

Tin Stannum Sn

Gold Aurum Au

Potassium  Kalium K

Lead Plumbum Pb

EVALUATION

1. How many elements are discovered now?
2. Write the symbols for the following elements: silicon, iodine, fluorine, sulphur, silver, Iron, copper, potassium and sodium.

CLASSIFICATION OF ELEMENTS

Elements can be classified into metals and non-metals.

Examples of metals include iron, zinc, tin, aluminium, copper etc.

Examples of non-metals are: Chlorine, oxygen, sulphur, fluorine, hydrogen etc.

Some elements however possess the properties of metals as well as non-metals. They are called metalloids, examples are silicon and germanium.

THE DIFFERENCES BETWEEN METALS AND NON-METALS

Metal Non – metals

1.  They are solids (except mercury) They are solids, liquids and gases

2.  Good conductors of heat   Poor conductors of heat and electricity

and electricity (except graphite which conduct electricity)

3.  Malleable Brittle

4.  Ductile   Not ductile

5.  Shiny   Not shiny

1. Often very dense Usually less dense(low density)

(high density)

EVALUATION

1. What are metalloids?
2. State two differences between metals and non-metals.

VALENCY

Valency is the combining power of an element. It can also be defined as the number of hydrogen atoms that can combine with or replace one atom of that element.

Valency of an element depends on the structure of that element. At times it corresponds to the number of electrons in the outermost shells called valence electrons.

Below are the valencies of some elements:

Element Symbol Valency

Aluminium Al  +3

Argon  Ar  Nil

Calcium Ca  +2

Chlorine Cl  -1

Sulphur S -2, -4 or -6

Sodium Na  +1

Magnesium Mg  +2

Copper  Cu  +1 or +2

Carbon  C  -2 or -4

Barium  Ba  +2

Silver  Ag  +1

Iron  Fe  +2 or +3

Valencies have either positive or negative values showing whether electrons are gained or lost. If an element gains electrons, its value is negative but positive when it loses electrons.

Generally, metals exhibit positive valencies while non – metal tend to have negative valencies. Some element exhibit more than one valency. Valency can also be called oxidation number or state.

RADICALS

A radical is a group of atoms having an electric charge either positive or negative which keeps its identity and react as a single unit. Any small group of atoms carrying a negative charge is called an acid radical. Examples of acid radicals include S0₄^2-, C0₃^2-, N0₃^–

The valency of a radical corresponds to the charge it carries.

Radical  Formula Valency

Ammonium  NH₄⁺ +1

Hydroxide 0H^–  -1

Trioxonitrate(V) N0₃^–  -1

Dioxonitrate(III) N0₂^–  -1

Trioxocarbonate(IV) C0₃^2-   -2

Tetraoxosulphate(VI) S0₄^2-  -2

Hydrogen trioxocarbonate   HC0₃^–  -1

GENERAL EVALUATION/REVISION

1. Define (i) valency (ii) Radical
2. Write the valency of: a) Oxygen (b) Potassium c) Sulphur d) S0₄^2- e) NH₄⁺
3. Classify the following into physical or chemical changes: a) Rusting of iron b) Fermentation of palm wine c) Evaporation of a salt solution d) Melting of ice

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio. Pg 26, 32-33

WEEKEND ASSIGNMENT

1. The combining power of oxygen is (a)+2 (b)-2 (c)-1 (d)+1
2. Which of the following is a metalloid? (a) sulphur (b) iron (c) silicon (d) carbon
3. The symbol Au represents (a) silver (b) lead (c) copper (d) gold
4. Which of the following elements is used as a standard in defining valency?

(a) oxygen (b) copper (c) carbon (d) hydrogen

1. Which of the following metals is a liquid at room temperature?
   1. iron (b) gold (c) tin (d) mercury

THEORY

1.  a.  Define an element.

1. Write the symbols of the following elements

   (i) Manganese (ii) Caesium (iii) Cobalt

2.  a.  What are metalloids?

1. Give two differences between metals and non-metal

WEEK FIVE

TOPIC: COMPOUNDS AND MIXTURES

CONTENT

• COMPOUND
• FORMULAE OF COMPOUNDS
• MIXTURES
• DIFFERENCES BETWEEN COMPOUNDS AND MIXTURES

COMPOUND

A Compound is a substance which contains two or more elements chemically combined together. A compound is formed as a result of chemical change.

Examples of compounds are

Compound Constituent Elements

Water  Hydrogen, oxygen

Sand  silicon, oxygen

Limestone calcium, carbon, oxygen

Common salt sodium, chlorine

Ethanol carbon, hydrogen, oxygen

PROPERTIES OF A COMPOUND

1. It has properties different from those of its component elements.
2. Its formation often requires large amount of heat.
3. It cannot be separated by physical means.
4. The components of a compound have a fixed ratio by mass.
5. Compounds are homogenous.

    

EVALUATION

1. Define a compound.
2. Give three examples of a compound.

FORMULAE OF COMPOUNDS

When an element exists as a molecule, a number is written as a subscript after the symbol of that element. For example, hydrogen is written as H₂ and oxygen as 0₂.

A compound contains whole numbers of atoms of the component elements. Its molecular formula is written as follows.

1. The symbols of all the component elements are written close together as a group.
2. The number of atoms of each component element is written as a subscript after the symbol of that element.

Examples

 Compound Formula

 Hydrochloric acid HCl

 Water  H₂0

 Ammonia NH₃

 Carbon(IV)oxide C0₂

 Lead II chloride PbCl₂

 Calcium trioxonitrate(V)  Ca(NO₃)₂

WRITING FORMULA FROM VALENCIES

Formulae of compounds can be deduced from the valencies of the component elements or radicals, following the rules below.

1. Write the symbols of the element or radicals in a compound
2. Write their valencies below the symbols of elements/radicals
3. Exchange their valencies.
4. Now write the formula of the compound bringing the symbols of the element or radicals together

Examples

1. Write the formula of sodium tetraoxosulphate(VI)

   Rule 1 Na S0₄

   Rule 2 & 3 1 2

   Rule 4 Na₂S0₄

1. Write the formula of calcium chloride

   Rule 1 Ca Cl

   Rule 2 & 3 2 1

   Rule 4 CaCl₂
   

EVALUATION

1. Write the formulae of; (i) tetraoxosulphate(vi) acid (ii) Magnesium Chloride
2. State three properties of a compound

MIXTURES

A mixture contains two or more constituents which can easily be separated by physical methods.

Examples of mixtures with their constituents are outlined below:

Mixture Constituents

Air  Oxygen, Carbon (iv)oxide, nitrogen, rare gases, dust, moisture

Soil  Sand, clay, humus, water, air, mineral salts

Urine  urea, water, mineral salt

Palm wine  water, sugar, alkanol, mineral salts, vitamins, yeast, protein, fat

Coca-cola  water, sugar, cola, CO₂

Milk  water, sugar, fat, protein, mineral salts, vitamin

Sea water  water, mineral salts, bacteria, remains of organic matter

Brass  copper and zinc

DIFFERENCES BETWEEN MIXTURES AND COMPOUNDS

Mixture  Compound

1.  It may be homogenous  It is always homogenous.

 or heterogeneous.

2.  It can be separated into  It cannot be separated into its

 its constituents by physical  components by physical means.

 means

3.  The constituents can be  The components are present in a

 added in any ratio by mass  fixed ratio by mass. Hence a

 Hence a mixture cannot be  compound can always be repre-

 represented by a chemical  sented by a chemical formula.

 Formula.

4.  The properties of a mixture  The properties of a compound

 are the sum of those of its  are entirely different from those

 individual constituents.  of its components.

EVALUATION

1. List five (5) compounds and their formulae
2. What is a mixture?
3. State four differences between compound and mixture

    

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio. Pg 11, 36 to 37

GENERAL EVALUATION/REVISION

1. State the valency of the following elements and radicals: Na, K, S, O, SO₄^2-, NO₃^–, CO₃^2-
2. Write the formula of: a) Lead (ii) tetraoxosulphate (vi) b) Hydrochloric acid c) Sodium trioxocarbonate (iv) d) Calcium hydroxide

WEEKEND ASSIGNMENT  

1. Which of the following is a mixture? (a) water(b) sugar(c) milk (d) starch
2. Which of the following is a compound? (a) water (b) soil (c) diamond (d) graphite
3. Which of these formulae represents ammonia? (a) NH₃ (b) NH₄⁺ (c) NH₂ (d) CH₄
4. The formula for sand is (a) C0₂ (b) SO₂ (c) NO₂ (d) SiO₂
5. Compounds are always (a) heterogeneous (b) homogeneous (c) homogeneous or heterogeneous (d) chemogeneous

    

THEORY

1.  a. Define (i) Compound (ii) Mixture

 b. Give two examples each of compound and Mixtures

2.  a. State four differences between compound and mixture

 b. What is the formula of

i) tetraoxosulphate (vi) acid

ii) Ammonium sulphide

 iii) Sodium tetraoxophosphate

WEEK SIX

TOPIC: STANDARD SEPARATION TECHNIQUES

CONTENT

• STANDARD SEPARATION TECHNIQUES

   

  STANDARD SEPARATION TECHNIQUES
  

The importance of separating a mixture into its constituents cannot be over emphasized since most substances are needed in their pure form. There are many standard separation techniques. Some of these separating techniques are filtration, centrifugation and decantation. Others include sieving, magnetic separation and sublimation, evaporation, crystallization, fractional precipitation, distillation, fractional distillation, using separating funnel and chromatography.

FILTRATION

Filtration is a separation technique that involves separating an insoluble solid from liquid using a filter. For example, a mixture of chalk particles in water can be separated using filtration technique. Filtration is used in industries such as water purification plants and breweries.

CENTRIFUGATION

A CENTRIFUGE MACHINE

Centrifugation is a standard separation technique used to separate a mixture of insoluble solid from liquid by using a centrifuge. A centrifuge is a machine which can spin test tubes containing suspensions at high speed. Centrifugation is often used when there is only a small amount of material. In hospitals, blood samples are centrifuged to separate the blood cells from the plasma.  

DECANTATION

Decantation is a separation technique used to separate a mixture containing insoluble solid from a liquid. This is done when the mixture is allowed to settle down with the upper clear liquid carefully poured or decanted into a clean container thereby leaving the lower solid in the container originally containing the mixture. This is a quick but inaccurate method of separating the components of a mixture.

EVAPORATION

Evaporation is a separation technique used to recover soluble solute from its solvent. For example salt can be separated from salt solution by evaporation.

A Salt Evaporation Pond

Evaporation is used in salt –making industries.

CRYSTALLIZATION

Crystallization is used to obtain pure crystals of salts which decompose easily on heating from its solution. The solution is concentrated by heating. It is allowed to cool down and crystals start to form. To induce crystal formation:

1. add crystals of the salt (seedling)
2. scratch the inside of the container with a glass rod

Crystallization is used in industries where purity of the product is important, such as in drug industries and sugar industries.

FRACTIONAL CRYSTALLIZATION

It is used to separate two or more solutes (solids) which are present in the same solution. The solutes to be separated must have different solubilities at different temperatures. Starting from a particular temperature, as cooling of the solution of those solutes takes place, the crystals of the relevant solutes appear leaving the other solutes in the solution.

EVALUATION

1. Explain briefly the following methods of separation of mixtures: (a)  Filtration (b) Decantation (c) Centrifugation
2. Explain how a pure sample of copper (II) tetraoxosulphate (VI) crystals can be obtained from its solution in the laboratory.
3. How would you separate a mixture of PbCl₂ and NaCl

PRECIPITATION

In precipitation, a difference in the solubility of a solid in two different miscible liquids is used. For example, FeS0₄ is soluble in water but not on ethanol. If ethanol is added to a solution of FeS0₄ in water, the FeS0₄ will be precipitated out of the solution and filtered out.

SUBLIMATION

Sublimation is the change of state from solid to gas directly on application of heat. Examples of substances that sublime are iodine and ammonium chloride. Sublimation can be used to separate these substances. The pure crystal recovered is the sublimate.

DISTILLATION

This is used to recover a solvent from a solution. It involves vapourising a liquid and then condensing the vapour into a liquid called distillate. The solute and other impurities remain in the distillation flask. It is used in gin and water distilleries to manufacture gin and distilled water.

FRACTIONAL DISTILLATION

This is used to separate a mixture of two or more miscible liquids based on their boiling points. When two liquids have boiling points that are very close (less than 100^oC the use of simple distillation becomes difficult. A fractionating column is inserted into the distillation flask. It is used to separate crude oil into fractions, separation of liquid air into oxygen and nitrogen, manufacture of spirits and to separate benzene and methyl benzene mixture.

EVALUATION

1. State the major difference between distillation and fractional distillation in terms of (a) Features of the apparatus (b) Mixtures to be separated

2. Explain the following separation techniques

1. Precipitation
2. Sublimation

SEPARATING FUNNEL

This is used to separate immiscible liquids. It depends on the densities of the two liquids. The less dense will be on top and the denser below. It is used to separate water and kerosene

SIEVING

This is used to separate solid particles of different sizes. Particles smaller than the size of the sieve (mesh) pass through leaving behind particles of larger sizes. It is used in gold and diamond mines and in garri industries.

MAGNETIC SEPARATION

This is used to separate magnetic substances from non-magnetic particles. It is used in mining and steel industries. It can be used to remove magnetic impurities from tin ores. It can be used to separate iron filings from sulphur powder.

CHROMATOGRAPHY

This method uses a solvent moving over an adsorbent medium (paper) which is porous to separate mixtures of solutes.

Types

1. Paper chromatography
2. Thin layer chromatography
3. Gas chromatography
4. Column chromatography

In paper chromatography, a solution, such as ink, is spotted into the paper near one end. The paper is dipped into an appropriate solvent such as water or ethanol in a closed air-tight jar. The solvent moves up the paper. The paper is removed and dried. The different spots on the paper show the different substances the solution (ink or dye) contains.

It is used in medicine to analyze blood. In industry, it is used to identify petroleum fractions. It is also used in scientific research.

CRITERIA FOR PURITY

1. The melting point and boiling point of a pure substance are fixed but change in the presence of impurities. Impurities lower the melting point of a substance and increase its boiling point
2. A pure substance gives one spot on a paper chromatogram.

    

GENERAL EVALUATION

1. Explain the following separation techniques. Magnetic separation, paper chromatography and sieving
2. Describe how you would separate a mixture of NaCl, PbCl₂ and NH₄Cl
3. What method can be applied to separate a mixture of iron filings and sulphur
4. Mention two criteria for purity of a substance.

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio.Pg 16 to 20

WEEKEND ASSIGNMENT

1. A mixture of oil and water can be separated by (a) sublimation (b) evaporation to dryness

   (c) using a separating funnel (d) fractional distillation

2. Fractional distillation is used to separate (a) an insoluble substance from a soluble volatile substance (b) liquids with differing boiling points (c) gas, liquid or solid impurities from a mixture (d) liquid with close boiling points
3. Which of the following separating techniques can be used to separate a mixture of iodine and sodium chloride? (a) distillation (b) evaporation (c) sublimation (d) decantation
4. Which of the following is not a type of chromatography ?(a) thin layer (b) gas (c) paper

   (d) glass

5. Which of the following is a quick but inaccurate way of separating mixture? (a) decantation (b) evaporation (c) filtration (d) distillation

THEORY

1. Explain briefly the following separation techniques (a) evaporation (b) filtration (c) fractional distillation
2. Mention two criteria for purity of a substance.

WEEK SEVEN

TOPIC: PARTICULATE NATURE OF MATTER

CONTENT

• ATOMS AND MOLECULES
• IONS
• DALTON’S ATOMIC THEORY
• MODIFICATIONS OF DALTONS ATOMIC THEORY

ATOMS AND MOLECULES

Matter is made up of discrete particles. The main ones are atoms, molecules, and ions.

An atom is the smallest part of an element which can take part in a chemical reaction.

A molecule is the smallest particle of a substance that can exist alone and still retains the chemical properties of that substance. Molecules are made up of atoms.

Atomicity of an element is the number of atoms in one molecule of the element.

We have monatomic, diatomic and triatomic for those elements that contain one atom, two atoms and three atoms respectively in their molecules.

Examples:

Element  Atomicity

Hydrogen  Diatomic

Oxygen   Diatomic

Nitrogen  Diatomic

Neon Monoatomic

Helium Monoatomic

Argon Monoatomic

EVALUATION

1. Define an atom.
2. Give two examples of diatomic molecules.

IONS

An ion is an atom or group of atoms which carries an electric charge. Such groups of atoms that carry either a positive or negative charge are called RADICALS.

An acid radical is thus a small group of atoms carrying a negative charge that keeps its identity. Examples include S0₄^2-, N0₃^– e.t.c.

Generally ions are grouped as cations and anions. Cations are positively charged ions e.g Ca²⁺, Na⁺, NH₄⁺ e.t.c.

Anions are negatively charged ions e.g.. C0₃^2-, S0₄^2-, Cl^–, OH^–, etc.

EVALUATION

1. What are ions?
2. State the cation and anion present in (I) H₂S0₄ (ii) NaCl (iii) FeS0₄

DALTON’S ATOMIC THEORY

John Dalton, British Physicist and Chemist (1808) proposed the atomic theory thus:

1. All elements are made up of small indivisible particles called atoms.
2. Atoms can neither be created nor destroyed in any chemical reaction.
3. Atoms of the same elements are exactly alike in aspect and are different from atoms of all other elements.
4. Atoms of different elements can combine in simple whole number ratios to form compounds.
5. All chemical changes result from the combination or separation of atoms

MODIFICATIONS OF DALTON’S ATOMIC THEORY

Due to new discoveries in the twentieth century, Dalton’s atomic theory cannot hold in its entirety. There is need for its modification.

1. The first statement has been proved wrong by Rutherford’s discovery of protons, electron and neutrons as constituents of the atom. An atom is not an indivisible solid piece.
2. The second statement still holds good for ordinary chemical reactions. During nuclear reactions, however, the nucleus can be broken into simpler atoms giving out large amount of heat (nuclear fission). This destroys the atoms involved.
3. The discovery of isotopes makes the third statement unacceptable. Chlorine for example has two atoms with different nucleus content and hence different relative atomic masses although the same proton numbers.
4. The fourth statement is true only for inorganic compounds which contain a few atoms per molecule. Carbon forms very large organic molecules such as proteins, starch and fats which

   contain thousands of atoms.

GENERAL EVALUATION/REVISION

1. State the modifications of the Dalton’s atomic theory.
2. A mixture contains propanone, ethanol and water with boiling point of 56⁰C, 78⁰C and 100⁰C respectively.
   1. What method will be used to separate the liquids
   2. Name the first liquid that will distil over. Explain your answer
   3. Name an industrial process that uses fractional distillation

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio. Pg 25-26

WEEKEND ASSIGNMENT

1. Which of the following is not a constituent of the atom (a) proton (b) electron (c) neutron

   (d) isotope

2. Which of the following statement about an atom is not correct? (a) it is indivisible (b) it is destructible in some cases (c) it is the smallest part of a substance that takes part in a reaction (d) it is made up of protons, neutrons and electrons
3. Which of the following is a liquid at room temperature? (a) copper (b) gold (c) mercury

   (d) silver

4. How can you separate a mixture of iron filings and sulphur powder? (a) distillation

   (b) chromatography (c) magnetization (d) evaporation

5. What is the atomicity of neon? (a) monoatomic (b) diatomic (c) triatomic (d) polyatomic

THEORY

1. Give any two postulates of the Dalton’s atomic theory.
2. (a)  Differentiate an atom from a molecule.

   (b) How will an atom become an ion?

WEEK EIGHT

IUPAC NOMENCLATURE OF CHEMICAL COMPOUNDS

CONTENT

Naming of:

—- binary compounds

—- radials and compounds having elements with variable oxidation numbers.

—- tertiary and quartenary compounds.

—- compounds with cations replaced with hydrogen.

NAMING OF BINARY COMPOUNDS

Nomenclature: This is the system of naming chemical compounds. The system is called IUPAC (International union of pure and applied chemistry). The naming is determined by the constituent elements in the compound and the oxidation number if necessary.

In naming binary compounds (compounds with only two elements), electropositive elements (cations) are usually named first while the electronegative elements (anions) come last with a modification of the name end with – ide.

Examples:

Formula IUPAC name

MgO Magnesium oxide

H₂S Hydrogen sulphide

NH₄Cl Ammonium chloride

NaH Sodium hydride

But in cases where the two elements involved are non-metals, the above rule is not followed. For example, H₂O (water) NH₃ (ammonia) and PH₃ (phosphine)

EVALUATION

Name the following compounds: (a) NaCl (b) CaO (c) H₂O₂.

NAMING OF RADICALS AND COMPOUNDS HAVING ELEMENTS WITH VARIABLE OXIDATION NUMERS

Radicals (group of atoms of element carrying electrical charge) are treated as a single element when naming their compounds.

Examples of radicals with their names are as follows:

Radical IUPAC NAME

NH4⁺ Ammonium ion

OH
Hydroxyl ion

But in naming acid radicals, the oxidation number of elements is indicated by Roman numbers in bracket.

Example:

Formula IUPAC

NO₂ Dioxonitratei(iii) ion

NO₃^– Trioxonitrate(v) ion

CO₃^2- Trioxocarbonate(iv) ion.

Also the compounds having elements with Roman numbers in bracket indicating their oxidation numbers in that compound

Examples

Formula IUPAC

FeO Iron (ii) oxide

Cu₂O Copper (i) oxide

MgCO₃ Magnesium trioxocarbonate (iv)

EVALUATION

1. Name the following compounds (a) Fe₂O₃ (b) CuO
2. What are the oxidation numbers of Fe and Cu in (1) above?

NAMING TERTIARY COMPOUNDS AND QUARTENARY COMPOUNDS.

These are compounds containing more than two elements.

Examples are oxo-acids, normal salts, and acid salts.

Acid IUPAC

HNO₃ Trioxonitrate(v) acid

H₂SO₄ Tetraoxosulphate (vi) acid

H₃PO₄ Tetraoxophospate (v) acid  

Examples of Normal Salts.

Normal salts IUPAC

KNO₃ Potassium trioxonitrate (iv)

NaSO₄ Sodiumtetraoxosulphate (vi)

CuCO₃ Copper (ii) trioxocarbonate (iv)

EVALUATION

1. Determine the oxidation number of: a) C in H₂CO₃ b) Mn in KMnO₄ c) Cu in CuSO₄
2. Name the compounds in 1 above

NAMING OF COMPOUNDS WHOSE CATIONS HAS BEEN PARTIALLY REPLACED WITH HYDROGEN IONS.

In naming compounds whose cations have been partially replaced with hydrogen ion, the cations is named first followed by hydrogen, then the radicals present indicating the roman number standing for the oxidation number of the element that is combined with oxygen to form the radical.

E.g Formula IUPAC

NaHSO₄ Sodium hydrogen tetraoxosulphate (vi)

KHSO₃ Potassium hydrogen trioxosulphate (iv)  

GENERAL EVALUATION/REVISION:

1. Determine the following oxidation number of a) C in LiHCO₃ b) S in KHSO₄ and name the compounds
2. Write the chemical formula of the following compounds a) Oxochlorate (I) acid b) Iron (ii) tetraoxosulphate (VI) pentahydrate
3. State the uses of the following laboratory apparatuses a) Condenser b) Kipp’s apparatus c)Tripod stand

READING ASSIGNMENT

• Practical Chemistry for Senior Secondary Schools By Godwin O. Ojokuku pg 20-28.

WEEKEND ASSIGNMENT

1. The compound Na₂S is called ____ (a) Sodium (ii) sulphate (b) Sodium sulphur (c) Sodium sulphide (d) Sodium sulphite.
2. The formula of sulphur (iv) oxide is (a) SO₄ (b) SO₂ (c) S₂O₄ (d) S₄O₂
3. Ammonium chloride can be written as (a) NH₄Cl (b) NH₃Cl₂ (c) NH₄HCl

   (d) NH₄OH

4. The IUPAC name of NaHSO₄ is (a) Sodium bicarbonate (b) Sodium tetraoxosulphate (vi) acid (c) Sodium sulphate (c) Sodium hydrogen tetraoxosulphate (vi)
5. Which of the following compounds have cation with variable oxidation state.

   (a) FeO₃ (b) ZnCO₃ (c) CuO (d) KU

THEORY

1. Name the following compounds (a) Fe₂O₃ (b) KMnO₄ (c) KClO₃
2. Calculate the oxidation number of (a) Sulphur in H₂SO₄ (b) Carbon in CuCO₃

WEEK NINE

ATOMIC NUMBER, RELATIVE ATOMIC MASSES, ISOTOPES AND CALCULATIONS

CONTENT

• ATOMIC NUMBER AND MASS NUMBER
• ISOTOPES
• CALCULATIONS OF RELATIVE ATOMIC MASS

CONSTITUENTS OF AN ATOM

Atoms are made up of sub-particles. Protons, electrons and neutrons. Proton has a positive charge, electron has a negative charge and neutron has no charge.

Atomic number and mass number

The atomic number of an element is the number of protons in the nucleus of its atom.

Mass number or atomic mass of an element is the sum of the number of protons and neutrons in the nucleus of its atom.

Mass Number = Number of proton + Number of neutron

An element X can be represented as

_ZX^A

where A= Atomic mass or mass number

Z= Atomic number

e.g.  40  mass no = 40

  Ca

1. atomic no = 20

EVALUATION

1. State the constituents of an atom.
2. What is the number of proton in the following elements?

   (a)  11_B  (b)  12_C

   1. 6

ISOTOPES

Isotopy is the occurrence of atoms of elements having the same atomic number but different mass numbers. This is due to the difference in the number of neutrons present in the atoms. The atoms that exhibit isotopy are called ISOTOPES.

Examples of atoms that exhibit isotopy are chlorine 35_Cl and 37 _Cl

Carbon- ¹² _C, ¹³ _C and ¹⁴ _C

Potassium – ³⁹K₁₉ and ⁴¹K₁₉

Oxygen  – ¹⁶O₁₆ and ¹⁸O₁₆    

EVALUATION

1. Define isotopy.
2. Write the isotopes of chlorine.

CALCULATION OF RELATIVE ATOMIC MASS

The following is an example of calculation of relative atomic mass of an element from percentage abundance of its isotopes.

1. X is an element which exists as an isotopic mixture containing 90% of ³⁹X₁₉ and 10% of ⁴¹X₁₉

1. How many neutrons are present in the isotope ⁴¹X
2. Calculate the mean relative atomic mass of X

Solution

1. Neutrons in ⁴¹X₁₉

=  41-19 = 22

b.  R.A.M  =  90  x  39  +  10  x  41

1. 100

=  90  x  39  +  41  x  10

100

=  3920  =  39.20

100

EVALUATION

1. How many neutrons are present in the isotope ³⁷Cl₁₇ ?
2. A given quantity of chlorine contains 75% ³⁵Cl₁₇, and 25% ³⁷Cl₁₇, determine the relative atomic mass of chlorine.

    

CALCULATIONS

1. The following are more examples of calculations of relative atomic masses of elements.
2. An element Y exist in two isotopic forms ³⁹Y₁₈ and ⁴⁰Y₁₈ in the ratio 3:2 respectively. What is the relative atomic mass of the element?

SOLUTION

R.A.M of Y  =  3  x  39  +  2  x  40

5 1 5 1

= 0.6 x 39 + 0.4 x 40

= 23.4 + 16

=  39.4

1. An element with relative atomic mass 16.2 contains two isotopes 16P8 with relative abundance 90% and mP8 with relative abundance 10%. What is the value of m?

SOLUTION

 16.2 =  90 x 16 + 10 x m

100

  16.2 =  9 x 16  + m

  10 10

 16.2 = 144 + m

10 10

 16.2 = 144 + m

10

 16.2 x 10 = 144 + m

 162 = 144 + m

 162 – 144 = m

  18 = m

The value of m is 18

GENERAL EVALUATION/REVISION

1. Consider the atoms represented below:

   ^q_X ^r_X

   p p

2. State the relationship between the two atoms.
3. What is the difference between them?
4. Give two examples of other elements which exhibit the phenomenon illustrated.
5. State the number of electrons, protons and neutrons present in the following atoms/ions
   1. Ca b) S^2- c) Al³⁺ d) P
6. If an element R has isotopes 60% ¹²R₆ and 40% ^xR₆ and the relative atomic mass of R is 12.4, find x.

READING ASSIGNMENT

• New School Chemistry for SSS by O.Y Ababio. Pg 48-49

WEEKEND ASSIGNMENT

1. The atomic number of an element is precisely

   (a) the number of protons in the atom (b) the number of electrons in the atom (c) the number of neutrons in the atom

2. An atom can be defined more accurately as (a) the smallest indivisible parts of an element that can take part in a chemical reaction (b) the smallest part of an element that can take part in a chemical reaction (c) a combination of protons, neutrons
3. The mass number is (a) proton number + neutron number (b) electron number + proton number (c) neutron number + electron number
4. Calculate the relative atomic mass of an element having two isotopes ¹⁰⁷ Ag and ¹⁰⁹Ag in the ratio 1:1 (a)106 (b)107 (c)108
5. An element X has two isotopes ^18.8X and ^15.8X in the proportion of 1:9 respectively. Find the relative atomic mass of X (a)16.1 (b)13.6 (c)16.8

THEORY

1.  (a)  Define the term isotopy.

(b)  Determine the number of electrons, protons and neutrons in each of the following: ³⁹K₁₉, ^63.5Cu₂₉

2.  If an element R has isotopes 60% of ¹²R₆ and 40% ^xR₆ and the relative atomic mass is 12.4, find x.

WEEK TEN

TOPIC: STRUCTURE OF THE ATOM

CONTENT

• Orbitals of The Atom
• Electronic Structure Of the Atom
• Filling Of Electrons in to Orbitals
• Quantum Numbers

ORBITALS OF THE ATOM

The region in space within which there is maximum possibility of finding an electron in an atom is called an ATOMIC ORBITAL. We have s, p, d, and f orbitals.

Shapes of s and p orbitals are as follows:

s-orbital

p_x orbital

p_y orbital p_z orbital

EVALUATION

1. Define atomic orbital
2. State the shape of (i) S-orbital (ii) P-orbital.

ELECTRONIC STRUCTURE OF THE ATOM

With the knowledge of atomic orbital the spectra of more complex atoms than hydrogen atom can be explained as follows:

a) that within a given principal quantum number or energy level, there are sub energy levels, i.e. energy levels otherwise called K,L,M,N,O,P AND Q shells have sub-energy levels otherwise called s,p,d and f orbitals

(b) The total number of sub-shells within a shell is given by n²

while the total maximum number of electrons is given by 2n² where n is the number of enregy level.

Energy Level Number of orbitals Maximum No of electrons

n = 1(K- shell) 1² =1 2´1^{2 =2}

n =2 (L- shell) 2² = 4 2´2^{2 = 8}

n = 3 (M- shell) 3² = 9 2´3² = 18

n = 4 (N- shell) 4² =16 2´ 4² = 32

n = 5 (O- shell) 5² = 25 2´ 5² =50

n = 6 (P-shell) 6² = 36 2´6² =72

n = 7 (Q – shell) 7² = 49 2´7² = 98

(c) In a given orbital there could be a maximum of only two electrons and electron in all orbitals of the same type within a principal quantum number possess equal energies.

(d) The electrons in the different sub- shells or orbitals within a principal quantum number do not all have equal energies.

The gradation of energies of orbitals is as follows:

1s< 2s<2p<3s<3p<3d<4s<4p<4d---

EVALUATION

1. State the first five energy levels.
2. Calculate the total no of electrons when n is equal to (i) 2 (ii) 4.

FILLING OF ELECTRONS IN ORBITALS

In filling electrons into the atoms of elements, considerations are given to the conditions laid down by Aufbau Principle, Pauli exclusion principle and Hund’s rule of maximum multiplicity.

AUFBAU PRINCIPLE states that electrons go in to fill orbitals of lower energy first before filling orbitals of higher energy and each orbital may hold up to two electrons.

PAULI EXCLUSION PRINCIPLE states that no two electrons have identical sets of the four quantum numbers {n, l, m and s in an atom}.

HUND’S RULE OF MAXIMUM MULTIPLICITY state that in filling degenerate orbitals with electrons, electrons go in singly first before pairing up occurs.

EVALUATION

State the following principle

{a} Aufbau Principle {b} Hund’s rule.

QUANTUM NUMBERS

Studies show that the energy of an electron may be characterized by four quantum numbers. These are

{1}The principal quantum number represented by n with integral values of 1,2,3,4 e.t.c.

{2}The subsidiary or Azimuthal quantum number represented by l with integral values

ranging from O to (n-1).

(3) The magnetic quantum number represented by m with integral values ranging

from –l to +l.

4. The spin quantum number represented by s with integral values – ¹/₂ and = ¹/₂.

Element Atomic Number Electronic configuration.

H 1 1S¹

He 2 1S²

Li 3 1S² 2S¹

Be 4 1S² 2S²

B 5 1S² 2S² 2P¹

C 6 1S² 2S² 2P²

N 7 1S² 2S² 2P³

O 8 1S² 2S² 2P⁴

F 9 1S² 2S² 2P⁵

Ne 10 1S² 2S² 2P⁶

Na 11 1S² 2S² 2P⁶ 3S¹

Mg 12 1S² 2S² 2P⁶ 3S²

Al 13 1S² 2S² 2P⁶ 3S² 3P¹

Si 14 1S² 2S² 2P⁶ 3S² 3P²

P 15 1S² 2S² 2P⁶3S²³3P³

S 16 1S² 2S² 2P⁶3S² 3P⁴

Cl 17 1S² 2S² 2P⁶ 3S² 3P⁵

Ar 18 1S² 2S² 2P⁶ 3S²3P⁶

K 19 1S² 2S² 2P⁶ 3S²3P⁶ 4S¹

Ca 20 1S² 2S² 2P⁶ 3S²3P⁶ 4S²

GENERAL EVALUATION

1. State the four quantum numbers.
2. Write the electronic configuration of the following a) Mg b) S^2- c) Ca²⁺ d) Si

    

   READING ASSIGNMENT
   

• New School Chemistry By O.Y. Ababio pg 49-54.

WEEKEND ASSIGNMENT

1. Which of the following orbitals is spherical in shape?

1. s (b) p (c) d (d) f

2. Which of the following shells have a maximum of eight electrons ?

1. k (b) l (c) m (d) n

3. 1s² 2s² 2p⁶ 3p¹ is the electronic configuration of

1. potassium (b) calcium (c) sodium (d) aluminum.

4. “No two electrons have identical sets of four quantum numbers”. This statement is

1. Aufbau principle (b) Pauli exclusion (c) Hund’s rule (d) Rutherford’s model.

5. Which of the quantum number is represented by L?

1. principal quantum no (b) subsidiary quantum no (c) magnetic quantum

(d) spin quantum.

THEORY

1. State the following principle (a) Pauli exclusion principle. (b) Aufbau principle.
2. Write the electronic configuration of

   (a) Oxygen

   (b) Calcium (c) Chloride ion (Cl^–) (d) Aluminum ion (Al³⁺)