{"id":1808,"date":"2023-10-02T06:25:52","date_gmt":"2023-10-02T06:25:52","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=1808"},"modified":"2023-10-02T06:32:11","modified_gmt":"2023-10-02T06:32:11","slug":"week-4-ss1-first-term-chemistry-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-4-ss1-first-term-chemistry-notes\/","title":{"rendered":"Week 4 &#8211; SS1 First Term Chemistry Notes"},"content":{"rendered":"<p>\u00a0<br \/>\n\u00a0<strong>WEEK FOUR<br \/>\n<\/strong><strong>TOPIC:  ELEMENTS, SYMBOLS &amp; VALENCY<br \/>\n<\/strong><strong>CONTENT<br \/>\n<\/strong><\/p>\n<ul>\n<li>\n<div>ELEMENTS AND SYMBOLS\n<\/div>\n<\/li>\n<li>\n<div>CLASSIFICATION OF ELEMENTS\n<\/div>\n<\/li>\n<li>\n<div>VALENCY<strong><br \/>\n\t\t\t\t\t<\/strong><\/div>\n<\/li>\n<\/ul>\n<p><strong>ELEMENTS AND SYMBOLS<br \/>\n<\/strong>An element is a substance which cannot be split into simpler units by ordinary chemical process. There are over one hundred known elements.<\/p>\n<p>\u00a0<strong>SYMBOLS OF ELEMENTS<br \/>\n<\/strong>There are three ways in which symbols of elements are derived.<\/p>\n<ol>\n<li>\n<div>From the first letter of the name of the element\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi1.png\" alt=\"\"\/>Element\u00a0\u00a0\u00a0\u00a0            Symbols<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi2.png\" alt=\"\"\/>Hydrogen\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0H<br \/>\nOxygen\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0          O<br \/>\nIodine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0I<br \/>\nFluorine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0F<br \/>\nNitrogen\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0N<br \/>\nSulphur\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0           S<br \/>\nCarbon\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0C<br \/>\nPhosphorus\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0P\n<\/li>\n<li>\n<div>The first letter written in capital letter and one other letter from its name written in small letter.\n<\/div>\n<\/li>\n<\/ol>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi3.png\" alt=\"\"\/>Element\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Symbol<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi4.png\" alt=\"\"\/>Chlorine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Cl<br \/>\nBramine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Br<br \/>\nCalcium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ca<br \/>\nAluminium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Al<br \/>\nMagnesium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Mg<br \/>\nBerylium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Be<br \/>\nHelium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0He<br \/>\nNeon\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ne<br \/>\nLithium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0L<\/p>\n<p>\u00a0<\/p>\n<ol>\n<li>\n<div>The symbols of some elements were derived from their Latin names.\n<\/div>\n<\/li>\n<\/ol>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi5.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi6.png\" alt=\"\"\/>Elements\u00a0\u00a0\u00a0\u00a0Latin name \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Symbols<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi7.png\" alt=\"\"\/>Mercury\u00a0\u00a0\u00a0\u00a0Hydragyrium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Hg<br \/>\nSodium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Natrium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Na<br \/>\nIron\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ferrum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Fe<br \/>\nCopper\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Cuprum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Cu<br \/>\nSilver\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Argentum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ag<br \/>\nTin\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Stannum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Sn<br \/>\nGold\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Aurum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Au<br \/>\nPotassium\u00a0\u00a0\u00a0\u00a0Kalium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0K<br \/>\nLead\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Plumbum\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Pb<\/p>\n<p>\u00a0<strong>EVALUATION<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div> How many elements are discovered now?\n<\/div>\n<\/li>\n<li>\n<div>Write the symbols for the following elements: silicon, iodine, fluorine, sulphur, silver, Iron, copper, potassium and sodium.\n<\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>CLASSIFICATION OF ELEMENTS<br \/>\n<\/strong>Elements can be classified into metals and non-metals.<br \/>\nExamples of metals include iron, zinc, tin, aluminium, copper etc.<br \/>\nExamples of non-metals are: Chlorine, oxygen, sulphur, fluorine, hydrogen etc.<br \/>\nSome elements however possess the properties of metals as well as non-metals. They are called metalloids, examples are silicon and germanium.<\/p>\n<p>\u00a0<strong>THE DIFFERENCES BETWEEN METALS AND NON-METALS<br \/>\n<\/strong><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi8.png\" alt=\"\"\/>Metal\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Non \u2013 metals<br \/>\n<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi9.png\" alt=\"\"\/>1.\u00a0\u00a0\u00a0\u00a0They are solids (except mercury)   They are solids, liquids and gases<br \/>\n2.\u00a0\u00a0\u00a0\u00a0Good conductors of heat\u00a0\u00a0\u00a0\u00a0           Poor conductors of heat and electricity<br \/>\nand electricity                               (except graphite which conduct electricity)<br \/>\n3.\u00a0\u00a0\u00a0\u00a0Malleable\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0            Brittle<br \/>\n4.\u00a0\u00a0\u00a0\u00a0Ductile\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Not ductile<br \/>\n5.\u00a0\u00a0\u00a0\u00a0Shiny\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0            Not shiny<\/p>\n<ol>\n<li>\n<div>Often very dense \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0            Usually less dense(low density)\n<\/div>\n<\/li>\n<\/ol>\n<p>(high density)  <\/p>\n<p>\u00a0<strong>EVALUATION<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>What are metalloids?\n<\/div>\n<\/li>\n<li>\n<div>State two differences between metals and non-metals.\n<\/div>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>VALENCY<br \/>\n<\/strong>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.<br \/>\nValency 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.<br \/>\nBelow are the valencies of some elements:<\/p>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi10.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi11.png\" alt=\"\"\/><strong>Element\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Symbol\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Valency<br \/>\n<\/strong><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi12.png\" alt=\"\"\/>Aluminium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Al\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+3<br \/>\nArgon\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ar\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Nil<br \/>\nCalcium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ca\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+2<br \/>\nChlorine\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Cl\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-1<br \/>\nSulphur\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 S\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0            -2, -4 or -6<br \/>\nSodium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Na\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+1<br \/>\nMagnesium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Mg\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+2<br \/>\nCopper\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Cu\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+1 or +2<br \/>\nCarbon\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0C\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-2 or -4<br \/>\nBarium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ba\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+2<br \/>\nSilver \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Ag\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+1<br \/>\nIron\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Fe\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0+2 or +3<\/p>\n<p>\u00a0Valencies 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.<br \/>\nGenerally, metals exhibit positive valencies while non \u2013 metal tend to have negative valencies. Some element exhibit more than one valency. Valency can also be called oxidation number or state.<\/p>\n<p>\u00a0<strong>RADICALS<br \/>\n<\/strong>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 S0<sub>4<\/sub><sup>2-<\/sup>, C0<sub>3<\/sub><sup>2-<\/sup>, N0<sub>3<\/sub><sup>&#8211;<\/sup><br \/>\n\t\tThe valency of a radical corresponds to the charge it carries.<\/p>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi13.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi14.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100223_0625_Week4SS1Fi15.png\" alt=\"\"\/>Radical\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Formula\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Valency<br \/>\nAmmonium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0NH<sub>4<\/sub><sup>+<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0           +1<br \/>\nHydroxide\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0           0H<sup>&#8211;<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-1<br \/>\nTrioxonitrate(V)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0           N0<sub>3<\/sub><sup>&#8211;<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-1<br \/>\nDioxonitrate(III)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0           N0<sub>2<\/sub><sup>&#8211;<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-1<br \/>\nTrioxocarbonate(IV)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0          C0<sub>3<\/sub><sup>2-\u00a0\u00a0\u00a0\u00a0<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-2<br \/>\nTetraoxosulphate(VI)                    S0<sub>4<\/sub><sup>2-<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-2<br \/>\nHydrogen trioxocarbonate\u00a0\u00a0\u00a0\u00a0         HC0<sub>3<\/sub><sup>&#8211;<\/sup>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0-1<br \/>\n\u00a0\u00a0\u00a0\u00a0<\/p>\n<p>\u00a0<strong>GENERAL EVALUATION\/REVISION<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>Define (i) valency (ii) Radical\n<\/div>\n<\/li>\n<li>\n<div>Write the valency of: a) Oxygen (b) Potassium c) Sulphur d) S0<sub>4<\/sub><sup>2-<\/sup> e) NH<sub>4<\/sub><sup>+<\/sup>\n\t\t\t\t<\/div>\n<\/li>\n<li>\n<div>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\n<\/div>\n<\/li>\n<\/ol>\n<p><strong>READING ASSIGNMENT<br \/>\n<\/strong><\/p>\n<ul>\n<li>\n<div>New School Chemistry for SSS by O.Y Ababio. Pg 26, 32-33\n<\/div>\n<\/li>\n<\/ul>\n<p>\u00a0<strong>WEEKEND ASSIGNMENT<br \/>\n<\/strong><\/p>\n<ol>\n<li>\n<div>The combining power of oxygen is (a)+2 (b)-2 (c)-1 (d)+1\n<\/div>\n<\/li>\n<li>\n<div>Which of the following is a metalloid?  (a) sulphur (b) iron (c) silicon   (d) carbon\n<\/div>\n<\/li>\n<li>\n<div>The symbol Au represents (a) silver (b) lead (c) copper (d) gold\n<\/div>\n<\/li>\n<li>\n<div>Which of the following elements is used as a standard in defining valency?\n<\/div>\n<\/li>\n<\/ol>\n<p>           (a) oxygen (b) copper (c) carbon (d) hydrogen<\/p>\n<ol>\n<li>\n<div>Which of the following metals is a liquid at room temperature?\n<\/div>\n<ol>\n<li>\n<div>iron (b) gold (c) tin (d) mercury\n<\/div>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<p>\u00a0<strong>THEORY<\/strong><br \/>\n\t\t1.\u00a0\u00a0\u00a0\u00a0a.\u00a0\u00a0\u00a0\u00a0Define an element.<\/p>\n<ol>\n<li>\n<div>    Write the symbols of the following elements\n<\/div>\n<p>(i)  Manganese (ii) Caesium     (iii) Cobalt\n<\/li>\n<\/ol>\n<p>2.\u00a0\u00a0\u00a0\u00a0a.\u00a0\u00a0\u00a0\u00a0What are metalloids?<\/p>\n<ol>\n<li>\n<div>    Give two differences between metals and non-metal\n<\/div>\n<\/li>\n<\/ol>\n<p><strong><br \/>\n\t\t\t<\/strong>\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0 \u00a0WEEK FOUR TOPIC: ELEMENTS, SYMBOLS &amp; VALENCY CONTENT ELEMENTS AND SYMBOLS CLASSIFICATION OF ELEMENTS&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,167],"tags":[],"class_list":["post-1808","post","type-post","status-publish","format-standard","hentry","category-posts","category-first-term-ss1-chemistry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/1808","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=1808"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/1808\/revisions"}],"predecessor-version":[{"id":1809,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/1808\/revisions\/1809"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=1808"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=1808"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=1808"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}