{"id":3463,"date":"2025-07-22T03:54:25","date_gmt":"2025-07-22T03:54:25","guid":{"rendered":"https:\/\/odeacademy.in\/?p=3463"},"modified":"2025-07-22T10:01:05","modified_gmt":"2025-07-22T10:01:05","slug":"matter-atoms-and-elements","status":"publish","type":"post","link":"https:\/\/thequickknowledge.com\/exam\/matter-atoms-and-elements\/","title":{"rendered":"Matter, Atoms &#038; Elements (Metals &#038; Non-Metals) \u2013 Chemistry | General Science"},"content":{"rendered":"<h4 style=\"text-align: center;\">Matter, Atoms &amp; Elements (Metals &amp; Non-Metals)<\/h4>\n<div class=\"CM8kHf j86kh\" data-hveid=\"CAkQAQ\">\n<div data-expression=\"frac{1}{v} + frac{1}{u} = frac{1}{f}\">\n<hr \/>\n<p>matter, which is defined as anything that has mass and occupies space. Everything around us \u2013 air, water, food, stones, stars, plants \u2013 is considered matter. <strong data-start=\"492\" data-end=\"510\">Modern science<\/strong>, however, classifies matter based on <strong data-start=\"548\" data-end=\"584\">physical and chemical properties<\/strong>. <strong>Key Physical Properties:<\/strong><\/p>\n<ul data-start=\"616\" data-end=\"825\">\n<li>Matter is made up of particles, these particles are extremely small and there is space between particles.<\/li>\n<li>Particles are continuously moving (kinetic energy) and attract each other.<\/li>\n<\/ul>\n<p><strong>States of Matter<\/strong> &#8211; Matter exists in three physical states (solid \u2194 liquid \u2194 gas)<\/p>\n<ul>\n<li>Matter changes state on changing temperature or pressure.<\/li>\n<li>Gases spread aroma over large distances due to rapid particle motion.<\/li>\n<\/ul>\n<p data-start=\"219\" data-end=\"250\"><strong data-start=\"223\" data-end=\"250\">Melting and Latent Heat<\/strong><\/p>\n<ul>\n<li>The temperature at which a solid turns into a liquid is its <strong data-start=\"476\" data-end=\"493\">melting point<\/strong> (e.g., <strong data-start=\"501\" data-end=\"526\">ice melts at 273.15 K<\/strong>).<\/li>\n<li data-start=\"529\" data-end=\"691\">\n<p data-start=\"531\" data-end=\"691\">Even when melting, temperature remains constant. The heat energy is used to overcome the attraction between particles, called <strong data-start=\"665\" data-end=\"690\">latent heat of fusion<\/strong>.<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"693\" data-end=\"740\"><strong data-start=\"697\" data-end=\"740\">Boiling and Latent Heat of Vaporization<\/strong><\/p>\n<ul data-start=\"741\" data-end=\"987\">\n<li>On further heating, liquids reach their <strong data-start=\"783\" data-end=\"800\">boiling point<\/strong> (e.g., water at <strong data-start=\"817\" data-end=\"835\">373 K or 100\u00b0C<\/strong>), where particles gain enough energy to overcome attraction and become <strong data-start=\"907\" data-end=\"917\">vapour<\/strong>.<\/li>\n<li>This extra energy is known as the <strong data-start=\"955\" data-end=\"986\">latent heat of vaporization<\/strong>.<\/li>\n<\/ul>\n<p data-start=\"994\" data-end=\"1028\"><strong data-start=\"998\" data-end=\"1028\">Sublimation and Deposition<\/strong><\/p>\n<ul data-start=\"1029\" data-end=\"1230\">\n<li>Some substances like <strong data-start=\"1052\" data-end=\"1063\">camphor<\/strong> or <strong data-start=\"1067\" data-end=\"1088\">ammonium chloride<\/strong> change <strong data-start=\"1096\" data-end=\"1126\">directly from solid to gas<\/strong>, this process called <strong data-start=\"1146\" data-end=\"1161\">sublimation<\/strong>.<\/li>\n<li><strong data-start=\"1165\" data-end=\"1179\">Deposition<\/strong> is the reverse where gas directly converting to solid.<\/li>\n<\/ul>\n<p data-start=\"1237\" data-end=\"1263\"><strong data-start=\"1241\" data-end=\"1263\">Effect of Pressure<\/strong><\/p>\n<ul data-start=\"1264\" data-end=\"1444\">\n<li><strong data-start=\"1266\" data-end=\"1289\">Increasing pressure<\/strong> and <strong data-start=\"1294\" data-end=\"1318\">reducing temperature<\/strong> can convert <strong data-start=\"1331\" data-end=\"1353\">gases into liquids<\/strong>.<\/li>\n<li>Example: Solid <strong data-start=\"1372\" data-end=\"1389\">CO\u2082 (dry ice)<\/strong> sublimates directly into gas at 1 atmosphere pressure.<\/li>\n<\/ul>\n<p data-start=\"1572\" data-end=\"1602\"><strong>Factors affecting evaporevaporation:<\/strong><\/p>\n<ul data-start=\"1605\" data-end=\"1813\">\n<li><strong data-start=\"1712\" data-end=\"1724\">Humidity<\/strong>: More humidity \u2192 slower evaporation<\/li>\n<li><strong data-start=\"1765\" data-end=\"1779\">Wind speed<\/strong>: Higher wind \u2192 faster evaporatio<\/li>\n<\/ul>\n<table>\n<thead>\n<tr>\n<th>Quantity<\/th>\n<th>Unit<\/th>\n<th>Symbol<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: center;\">Temperature<\/td>\n<td style=\"text-align: center;\">Kelvin<\/td>\n<td style=\"text-align: center;\">K<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Length<\/td>\n<td style=\"text-align: center;\">Metre<\/td>\n<td style=\"text-align: center;\">m<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Mass<\/td>\n<td style=\"text-align: center;\">Kilogram<\/td>\n<td style=\"text-align: center;\">kg<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Weight<\/td>\n<td style=\"text-align: center;\">Newton<\/td>\n<td style=\"text-align: center;\">N<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Volume<\/td>\n<td style=\"text-align: center;\">Cubic metre<\/td>\n<td style=\"text-align: center;\">m\u00b3<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Density<\/td>\n<td style=\"text-align: center;\">kg\/m\u00b3<\/td>\n<td style=\"text-align: center;\">kg m\u207b\u00b3<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\">Pressure<\/td>\n<td style=\"text-align: center;\">Pascal<\/td>\n<td style=\"text-align: center;\">Pa<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Pure, Mixture and Componats<\/strong><\/p>\n<p>For scientists, a pure substance has only one kind of particle and a uniform composition. A mixture is made up of two or more substances that are not chemically combined. Examples air, seawater soil etc.<\/p>\n<p><strong>Mixtures<\/strong>: Physical combination of substances; properties of constituents are retained.<\/p>\n<ul>\n<li><strong data-start=\"692\" data-end=\"716\">Homogeneous Mixtures<\/strong> \u2013 Uniform composition (e.g., salt water, sugar solution)<\/li>\n<li><strong data-start=\"778\" data-end=\"804\">Heterogeneous Mixtures<\/strong> \u2013 Non-uniform composition (e.g., oil and water, salt and sulphur)<\/li>\n<\/ul>\n<p><strong>Compounds:<\/strong> Chemical combination of two or more elements; fixed composition and new properties.<\/p>\n<p>Solutions involve a solute, solvent, and are classified as saturated, unsaturated, or supersaturated.<\/p>\n<p data-start=\"904\" data-end=\"1035\"><strong>Solution<\/strong> is a homogeneous mixture involve a solute, solvent, and are classified as saturated, unsaturated, or supersaturated.<\/p>\n<ul data-start=\"1037\" data-end=\"1141\">\n<li><strong data-start=\"1039\" data-end=\"1050\">Solvent<\/strong>: Substance present in a larger amount.<\/li>\n<li><strong data-start=\"1092\" data-end=\"1102\">Solute<\/strong>: Substance present in a lesser amount.<\/li>\n<\/ul>\n<p><strong>Properties of Solutions:<\/strong> Particles are very small. They don\u2019t scatter light. They are stable and can&#8217;t be separated by filtration. Types of Solutions:<\/p>\n<ul>\n<li>Solid in liquid (e.g., sugar in water)<\/li>\n<li>Gas in liquid (e.g., CO\u2082 in soda)<\/li>\n<li>Gas in gas (e.g., air)<\/li>\n<\/ul>\n<p><strong>Concentration of a Solution:<\/strong> Dilute solution: Less solute Concentrated solution: More solute Saturated solution: No more solute can dissolve Unsaturated solution: More solute can still dissolve<\/p>\n<p style=\"text-align: center;\">Mass by mass percentage = (Mass of solute\/Mass of solution)\u200b \u00d7100<\/p>\n<p data-start=\"345\" data-end=\"368\"><strong data-start=\"352\" data-end=\"368\">Suspensions:<\/strong><\/p>\n<ul data-start=\"369\" data-end=\"543\">\n<li><strong data-start=\"371\" data-end=\"399\">Non-homogeneous mixtures<\/strong> where particles remain suspended and visible.<\/li>\n<li><strong data-start=\"448\" data-end=\"493\">Particles can be separated by filtration.<\/strong><\/li>\n<li>Scatter light and settle down when undisturbed.<\/li>\n<\/ul>\n<p data-start=\"545\" data-end=\"565\"><strong data-start=\"552\" data-end=\"565\">Colloids:<\/strong><\/p>\n<ul data-start=\"566\" data-end=\"860\">\n<li><strong data-start=\"568\" data-end=\"594\">Heterogeneous mixtures<\/strong> with very small particles, Appear homogeneous but are not.<\/li>\n<li>Show <strong data-start=\"663\" data-end=\"681\">Tyndall effect<\/strong> (scattering of light).<\/li>\n<li>Stable and don\u2019t settle easily, <strong data-start=\"741\" data-end=\"763\">Cannot be filtered<\/strong>, but can be separated using <strong data-start=\"792\" data-end=\"810\">centrifugation<\/strong>.<\/li>\n<li>Examples include <strong data-start=\"831\" data-end=\"859\">milk, fog, shaving cream<\/strong>.<\/li>\n<\/ul>\n<p data-start=\"862\" data-end=\"888\"><strong data-start=\"869\" data-end=\"888\">Tyndall Effect:<\/strong><\/p>\n<ul data-start=\"889\" data-end=\"983\">\n<li>Scattering of light by colloidal particles, Can be observed in fog, forest mist, and milk.<\/li>\n<\/ul>\n<p data-start=\"985\" data-end=\"1026\"><strong data-start=\"992\" data-end=\"1026\">Physical and Chemical Changes:<\/strong><\/p>\n<ul data-start=\"1027\" data-end=\"1271\">\n<li><strong data-start=\"1029\" data-end=\"1048\">Physical change<\/strong>: No change in chemical composition (e.g., melting, boiling).<\/li>\n<li><strong data-start=\"1112\" data-end=\"1131\">Chemical change<\/strong>: Change in composition; new substances formed (e.g., burning).<\/li>\n<\/ul>\n<p style=\"padding-left: 40px;\"><strong data-start=\"1197\" data-end=\"1220\">Burning of a candle<\/strong> is both physical (melting) and chemical (burning).<\/p>\n<p style=\"padding-left: 40px;\">There are more than 100 known elements, with 92 naturally occurring.<\/p>\n<p><strong>Maharishi Kanad<\/strong> and Pakudha Katayama proposed that matter consists of indivisible particles called &#8220;Parmanu.&#8221; By the 18th century, scientific understanding advanced, leading to the discovery of <strong data-start=\"564\" data-end=\"596\">laws of chemical combination<\/strong>.<\/p>\n<p><strong>Laws of Chemical Combination<\/strong><\/p>\n<ul>\n<li><strong>Law of Conservation of Mass<\/strong> Proposed by Lavoisier, this law states: \u201cMass can neither be created nor destroyed in a chemical reaction.\u201d<\/li>\n<li><strong>Law of Constant Proportions<\/strong> Stated by Proust: \u201cIn a chemical substance, the elements are always present in definite proportions by mass.\u201d<\/li>\n<\/ul>\n<p data-start=\"833\" data-end=\"871\"><strong data-start=\"840\" data-end=\"871\">John Dalton\u2019s Atomic Theory<\/strong><\/p>\n<ol data-start=\"894\" data-end=\"1250\">\n<li>All matter is made of tiny particles called atoms.<\/li>\n<li>Atoms are indivisible and indestructible.<\/li>\n<li>Atoms of the same element are identical in mass and properties.<\/li>\n<li>Atoms of different elements differ in mass and properties.<\/li>\n<li>Atoms combine in whole number ratios to form compounds.<\/li>\n<li>The relative number and kinds of atoms in a compound are constant.<\/li>\n<\/ol>\n<p><strong>Atoms<\/strong><\/p>\n<ul>\n<li><strong data-start=\"1386\" data-end=\"1403\">Atomic radius<\/strong> is measured in <strong data-start=\"1419\" data-end=\"1438\">nanometres (nm).<\/strong><\/li>\n<\/ul>\n<\/div>\n<p>Dalton introduced the concept of <strong data-start=\"547\" data-end=\"562\">atomic mass<\/strong>, and the modern standard is based on the <strong data-start=\"604\" data-end=\"625\">carbon-12 isotope<\/strong>, with mass units in <strong data-start=\"646\" data-end=\"671\">unified mass unit (u)<\/strong>. (Hydrogen&#8217;s atomic mass = 1 u, oxygen = 16 u, etc.)<\/p>\n<ul>\n<li data-start=\"1287\" data-end=\"1361\">\n<p data-start=\"1289\" data-end=\"1361\"><strong data-start=\"1289\" data-end=\"1313\">Atomic mass unit (u)<\/strong> = 1\/12th the mass of one atom of <strong data-start=\"1347\" data-end=\"1360\">carbon-12<\/strong>.<\/p>\n<\/li>\n<\/ul>\n<p>Atoms are incredibly small and can&#8217;t exist independently; they usually combine to form <strong data-start=\"761\" data-end=\"774\">molecules<\/strong> or <strong data-start=\"778\" data-end=\"786\">ions<\/strong>. Molecules consist of one or more atoms held together tightly, while <strong data-start=\"856\" data-end=\"864\">ions<\/strong> are charged species formed by the gain or loss of electrons (e.g., Na\u207a, Cl\u207b).<\/p>\n<p>The <strong data-start=\"947\" data-end=\"960\">atomicity<\/strong> of elements describes how many atoms are present in their molecule form (e.g., O\u2082 = diatomic).<\/p>\n<ul>\n<li data-start=\"1477\" data-end=\"1551\"><strong data-start=\"1477\" data-end=\"1490\">Molecules<\/strong> can be monoatomic (Ar), diatomic (O\u2082), polyatomic (S\u2088), etc.<\/li>\n<li data-start=\"1477\" data-end=\"1551\"><strong data-start=\"1554\" data-end=\"1593\">Atoms of different elements combine<\/strong> in fixed ratios to form compounds.<\/li>\n<li data-start=\"918\" data-end=\"970\"><strong data-start=\"918\" data-end=\"929\">Valency<\/strong> is the combining capacity of an element.<\/li>\n<li data-start=\"973\" data-end=\"1037\"><strong data-start=\"975\" data-end=\"995\">chemical formula<\/strong> represents the composition of a compound.<\/li>\n<li data-start=\"973\" data-end=\"1037\"><strong data-start=\"1040\" data-end=\"1062\">Criss-cross method<\/strong> helps balance charges of ions to form a compound.<\/li>\n<li data-start=\"1115\" data-end=\"1190\"><strong data-start=\"1115\" data-end=\"1134\">Polyatomic ions<\/strong> require brackets if more than one is used in a formula, Examples include formulas of compounds like CaCl\u2082, Al\u2082O\u2083, NaNO\u2083, and (NH\u2084)\u2082SO\u2084.<\/li>\n<li data-start=\"1275\" data-end=\"1331\"><strong data-start=\"1275\" data-end=\"1293\">Molecular mass<\/strong> = Sum of atomic masses in a molecule.<\/li>\n<li data-start=\"1334\" data-end=\"1429\"><strong data-start=\"1334\" data-end=\"1355\">Formula unit mass<\/strong> applies to ionic compounds and is calculated similarly to molecular mass.<\/li>\n<\/ul>\n<p data-start=\"1334\" data-end=\"1429\">in the late 19th and early 20th centuries proved that atoms are made up of sub-atomic particles \u2014 electrons, protons, and later neutrons.<\/p>\n<ul>\n<li data-start=\"1334\" data-end=\"1429\">J.J. Thomson discovered the <strong>electron<\/strong> and proposed the &#8220;plum pudding&#8221; model where electrons were embedded in a positively charged sphere.<\/li>\n<li data-start=\"1334\" data-end=\"1429\">E. Goldstein discovered canal rays, leading to the identification of positively charged particles called <strong>protons<\/strong>.<\/li>\n<li data-start=\"1334\" data-end=\"1429\">James Chadwick discovered neutrons\u2014neutral subatomic particles found in the nucleus along with protons.<\/li>\n<\/ul>\n<p>Rutherford\u2019s gold foil (alpha-particle scattering) experiment revolutionized the understanding of <strong>atomic structure<\/strong>. The Bohr model of the atom was introduced to address the limitations of Rutherford\u2019s atomic model.<\/p>\n<ul>\n<li>Bohr proposed that electrons revolve in <strong>fixed orbits<\/strong> called energy levels or shells without radiating energy. These shells are designated as K, L, M, N&#8230; or n = 1, 2, 3, etc.<\/li>\n<li>Bohr and Bury proposed : a shell can hold a maximum of 2n\u00b2 electrons, and electrons fill the inner shells first. The outermost shell can hold a maximum of 8 electrons.<\/li>\n<li>Electrons in the outermost shell are called valence electrons, and their number determines the <strong data-start=\"884\" data-end=\"895\">valency<\/strong> of an element. If the shell is full, the atom is chemically inactive (like noble gases).<\/li>\n<\/ul>\n<p>The atomic number of an element is defined as the number of protons in its nucleus, denoted by &#8216;Z&#8217;. The mass number is the total number of protons and neutrons in an atom\u2019s nucleus, denoted by &#8216;A&#8217;.<\/p>\n<p>isotopes are atoms of the same element having the same atomic number but different mass numbers. For example, hydrogen has three isotopes: protium, deuterium, and tritium. (e.g., \u00b9H, \u00b2H, \u00b3H).<\/p>\n<\/div>\n<ul>\n<li>Isotopes have similar chemical properties but different physical properties.<\/li>\n<li>Applications of isotopes include their use in nuclear reactors, cancer treatment, and goitre treatment.<\/li>\n<\/ul>\n<p>Isobars are atoms of different elements with different atomic numbers but the same mass number, like calcium (Z = 20) and argon (Z = 18) both having a mass number of 40.<\/p>\n<h5><strong>Metals and Non-metals<\/strong><\/h5>\n<p data-start=\"335\" data-end=\"375\"><strong>Physical Properties of Metals<\/strong><\/p>\n<ol data-start=\"376\" data-end=\"966\">\n<li><strong data-start=\"379\" data-end=\"398\">Metallic Lustre<\/strong>: Metals in pure state have a shiny appearance.<\/li>\n<li><strong data-start=\"449\" data-end=\"461\">Hardness<\/strong>: Most metals are hard, though hardness varies.<\/li>\n<li><strong data-start=\"512\" data-end=\"528\">Malleability<\/strong>: Metals can be beaten into thin sheets.<\/li>\n<li><strong data-start=\"572\" data-end=\"585\">Ductility<\/strong>: Metals can be drawn into thin wires (e.g., gold is most ductile).<\/li>\n<li><strong data-start=\"656\" data-end=\"672\">Conductivity<\/strong>:\n<ul data-start=\"376\" data-end=\"966\">\n<li><strong data-start=\"679\" data-end=\"687\">Heat<\/strong>: Silver and copper are excellent heat conductors.<\/li>\n<li><strong style=\"font-size: 16px;\" data-start=\"743\" data-end=\"758\">Electricity<\/strong><span style=\"font-size: 16px;\">: Metals like copper and aluminium conduct electricity.<\/span><\/li>\n<\/ul>\n<\/li>\n<li><strong data-start=\"817\" data-end=\"829\">Sonority<\/strong>: Metals produce a ringing sound when struck.<\/li>\n<li data-start=\"376\" data-end=\"445\"><strong data-start=\"878\" data-end=\"895\">Melting Point<\/strong>: Generally high in metals, except for metals like gallium and caesium.<\/li>\n<\/ol>\n<ul>\n<li style=\"list-style-type: none;\"><\/li>\n<\/ul>\n<p data-start=\"968\" data-end=\"1012\"><strong data-start=\"975\" data-end=\"1012\">Physical Properties of Non-Metals<\/strong><\/p>\n<ol data-start=\"1013\" data-end=\"1280\">\n<li>Include carbon, sulphur, iodine, etc.<\/li>\n<li>Can be <strong data-start=\"1064\" data-end=\"1083\">solids or gases<\/strong>, except bromine (liquid).<\/li>\n<li><strong data-start=\"1113\" data-end=\"1129\">Not lustrous<\/strong>, <strong data-start=\"1131\" data-end=\"1150\">poor conductors<\/strong>, <strong data-start=\"1152\" data-end=\"1180\">not malleable or ductile<\/strong>.<\/li>\n<li>Produce <strong data-start=\"1193\" data-end=\"1210\">acidic oxides<\/strong> when burnt.<\/li>\n<li>Some non-metals like iodine are exceptions (lustrous).<\/li>\n<\/ol>\n<p data-start=\"1282\" data-end=\"1315\"><strong data-start=\"1289\" data-end=\"1315\">Important Observations<\/strong><\/p>\n<ul data-start=\"1316\" data-end=\"1519\">\n<li>Mercury is the only metal liquid at room temperature.<\/li>\n<li data-start=\"1316\" data-end=\"1371\">\u00a0Alkali metals like sodium and potassium can be cut with a knife.<\/li>\n<\/ul>\n<p><strong>Reaction with Air<\/strong><\/p>\n<ul>\n<li data-start=\"247\" data-end=\"399\">Metals combine with oxygen to form <strong data-start=\"284\" data-end=\"300\">metal oxides<\/strong>.\n<ul>\n<li data-start=\"247\" data-end=\"399\">Copper \u2192 forms black Copper(II) oxide.<\/li>\n<li data-start=\"247\" data-end=\"399\">Aluminium \u2192 forms Aluminium oxide.<\/li>\n<\/ul>\n<\/li>\n<li data-start=\"247\" data-end=\"399\">Metal oxides are usually <strong data-start=\"427\" data-end=\"436\">basic<\/strong>, but some like <strong data-start=\"452\" data-end=\"461\">Al\u2082O\u2083<\/strong> and <strong data-start=\"466\" data-end=\"473\">ZnO<\/strong> are <strong data-start=\"478\" data-end=\"492\">amphoteric<\/strong> (react acids &amp; bases both).<\/li>\n<li><strong data-start=\"530\" data-end=\"556\">Highly reactive metals<\/strong> like sodium &amp; potassium catch fire in air and are stored in <strong data-start=\"617\" data-end=\"629\">kerosene<\/strong>.<\/li>\n<li><strong data-start=\"633\" data-end=\"650\">Less reactive<\/strong> metals form a <strong data-start=\"665\" data-end=\"685\">thin oxide layer<\/strong> which protects them from further oxidation.<\/li>\n<li data-start=\"528\" data-end=\"630\"><strong data-start=\"732\" data-end=\"745\">Anodising<\/strong> thickens this oxide layer on aluminium.<\/li>\n<\/ul>\n<p><strong>Reaction with Water<\/strong><\/p>\n<ul>\n<li>Metals + Water \u2192 Metal Oxide + Hydrogen<\/li>\n<li>Metal Oxide + Water \u2192 Metal Hydroxide<\/li>\n<li>Potassium, Sodium \u2192 React violently with cold water<\/li>\n<li>Calcium \u2192 Reacts less violently<\/li>\n<li>Magnesium \u2192 Reacts only with hot water<\/li>\n<li>Iron, Zinc, Aluminium \u2192 React with steam, not cold water<\/li>\n<li>Lead, Silver, Gold \u2192 Do not react with water<\/li>\n<\/ul>\n<p>Reaction with Acids<\/p>\n<ul>\n<li><strong data-start=\"1372\" data-end=\"1417\">Metal + Dilute Acid \u2192 Salt + Hydrogen Gas<\/strong><\/li>\n<li><strong data-start=\"1420\" data-end=\"1437\">More reactive<\/strong> metals like <strong data-start=\"1450\" data-end=\"1456\">Mg<\/strong> react vigorously.<\/li>\n<li><strong data-start=\"1477\" data-end=\"1487\">Copper<\/strong> does not react with dilute HCl.<\/li>\n<li>Nitric acid does <strong data-start=\"1539\" data-end=\"1556\">not evolve H\u2082<\/strong> because it&#8217;s a <strong data-start=\"1572\" data-end=\"1598\">strong oxidising agent<\/strong>.<\/li>\n<li>Reactivity order: <strong data-start=\"1620\" data-end=\"1646\">Mg &gt; Al &gt; Zn &gt; Fe &gt; Cu<\/strong><\/li>\n<\/ul>\n<p><strong>Reaction with Solutions of Other Metal Salts<\/strong><\/p>\n<ul>\n<li>Displacement reaction: A more reactive metal displaces a less reactive one from its salt solution. E.g., Iron displaces Copper from copper sulphate.<\/li>\n<\/ul>\n<p><strong>Reactivity of Metals and the Reactivity Series<\/strong><\/p>\n<ul>\n<li>Reaction occurred in the copper sulphate solution, Iron is more reactive than copper, so it displaces copper from its solution. Fe (s) + CuSO\u2084 (aq) \u2192 FeSO\u2084 (aq) + Cu (s) [Displacement reaction.]<\/li>\n<\/ul>\n<p><strong>Reactivity Series: <\/strong>K &gt; Na &gt; Ca &gt; Mg &gt; Al &gt; Zn &gt; Fe &gt; Pb &gt; [H] &gt; Cu &gt; Hg &gt; Ag &gt; Au<\/p>\n<p data-start=\"760\" data-end=\"859\"><strong>Properties of Ionic Compounds<\/strong><\/p>\n<ul>\n<li><strong data-start=\"1644\" data-end=\"1663\">Physical state:<\/strong> Solid.<\/li>\n<li><strong data-start=\"1673\" data-end=\"1685\">Melting:<\/strong> They melt on heating.<\/li>\n<li><strong data-start=\"1710\" data-end=\"1725\">Solubility:<\/strong> Soluble in water, not in petrol or kerosene.<\/li>\n<li><strong data-start=\"1773\" data-end=\"1790\">Conductivity:<\/strong> Conduct electricity when dissolved in water.<\/li>\n<li><strong data-start=\"1837\" data-end=\"1851\">Inference:<\/strong>\n<ul>\n<li>Ionic compounds are crystalline solids with high melting and boiling points.<\/li>\n<li>They conduct electricity in molten or aqueous states due to free ions.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p data-start=\"119\" data-end=\"156\"><strong data-start=\"123\" data-end=\"156\">Properties of Ionic Compounds<\/strong><\/p>\n<ul data-start=\"157\" data-end=\"568\">\n<li><strong data-start=\"159\" data-end=\"178\">Physical Nature<\/strong>: Ionic compounds are solid and brittle due to strong electrostatic forces.<\/li>\n<li><strong data-start=\"256\" data-end=\"286\">Melting and Boiling Points<\/strong>: These compounds have high melting and boiling points due to strong inter-ionic attractions.<\/li>\n<li><strong data-start=\"382\" data-end=\"396\">Solubility<\/strong>: Soluble in water, but not in organic solvents like kerosene and petrol.<\/li>\n<li><strong data-start=\"472\" data-end=\"499\">Electrical Conductivity<\/strong>: Conduct electricity in molten or dissolved form, not in solid form.<\/li>\n<\/ul>\n<p data-start=\"570\" data-end=\"613\"><strong data-start=\"574\" data-end=\"613\">Occurrence and Extraction of Metals<\/strong><\/p>\n<ul data-start=\"614\" data-end=\"1155\">\n<li><strong data-start=\"616\" data-end=\"637\">Minerals and Ores<\/strong>: Naturally occurring elements\/compounds are called <strong data-start=\"689\" data-end=\"701\">minerals<\/strong>. When a mineral contains a high percentage of metal and is economically viable to extract, it is termed an <strong data-start=\"809\" data-end=\"816\">ore<\/strong>.<\/li>\n<li data-start=\"614\" data-end=\"817\"><strong data-start=\"820\" data-end=\"854\">Extraction Based on Reactivity<\/strong>:\n<ul data-start=\"614\" data-end=\"1155\">\n<li>Low Reactivity Metals: Extracted by heating alone (e.g., Mercury from cinnabar).<\/li>\n<li>Moderate Reactivity Metals: Extracted via roasting or calcination, followed by reduction (e.g., Zinc).<\/li>\n<li>High Reactivity Metals: Extracted by electrolysis (e.g., Sodium, Aluminium).<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p data-start=\"1156\" data-end=\"1182\"><strong data-start=\"1160\" data-end=\"1182\">Refining of Metals<\/strong><\/p>\n<ul data-start=\"1183\" data-end=\"1350\">\n<li data-start=\"1183\" data-end=\"1350\">\n<p data-start=\"1185\" data-end=\"1350\"><strong data-start=\"1185\" data-end=\"1210\">Electrolytic Refining<\/strong>: Used to purify metals like copper, zinc, gold. The impure metal is made the <strong data-start=\"1288\" data-end=\"1297\">anode<\/strong>, and the pure metal is deposited on the <strong data-start=\"1338\" data-end=\"1349\">cathode<\/strong>.<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"1352\" data-end=\"1369\"><strong data-start=\"1356\" data-end=\"1369\">Corrosion &#8211; <\/strong>The slow degradation of metals due to environmental exposure.<\/p>\n<ul data-start=\"1370\" data-end=\"1735\">\n<li data-start=\"1370\" data-end=\"1622\"><strong data-start=\"1454\" data-end=\"1464\">Silver<\/strong>: Turns black due to silver sulphide.<\/li>\n<li><strong data-start=\"1565\" data-end=\"1573\">Iron<\/strong>: Forms <strong data-start=\"1581\" data-end=\"1589\">rust<\/strong> in presence of moisture and air.<\/li>\n<li data-start=\"1370\" data-end=\"1622\"><strong data-start=\"1506\" data-end=\"1516\">Copper<\/strong>: Turns green due to basic copper carbonate.<\/li>\n<\/ul>\n<p><strong>Prevention of Corrosion<\/strong><\/p>\n<ul>\n<li>Painting, oiling, greasing Galvanising (coating with zinc) Chrome plating, anodising, or making alloys<\/li>\n<li>Galvanisation: Coating iron\/steel with zinc. Even if the zinc layer is scratched, iron doesn&#8217;t rust easily.<\/li>\n<\/ul>\n<p><strong>Alloying: Improving Metal Properties<\/strong><\/p>\n<ul>\n<li>Alloying improves metal properties by mixing them with other metals or non-metals. Example: Iron + Carbon \u2192 Stronger iron Iron + Nickel + Chromium \u2192 Stainless Steel (hard, rust-free)<\/li>\n<li>Alloy: A homogeneous mixture of two or more metals or a metal and a non-metal. Formed by melting and mixing elements in definite proportions.<\/li>\n<\/ul>\n<p><strong>Interesting Facts<\/strong><\/p>\n<ul>\n<li>24-carat gold is soft and not used in jewellery. 22-carat gold is used in India, alloyed with copper or silver.<\/li>\n<li>Amalgam: Alloy of mercury.<\/li>\n<li>Examples of alloys: Brass: Copper + Zinc Bronze: Copper + Tin Solder: Lead + Tin (used for joining wires)<\/li>\n<li>Iron Pillar of Delhi: Built 1600+ years ago. Resistant to rust due to advanced ancient technique. 8 m tall and weighs 6000 kg (6 tonnes).<\/li>\n<\/ul>\n<hr \/>\n<p><span style=\"color: #ff0000;\"><strong>Related Links<\/strong><\/span><\/p>\n<ul>\n<li><strong>General Science : Questions for Competitive Exams<\/strong> \ud83d\udd17<\/li>\n<\/ul>\n<p><strong><a href=\"https:\/\/thequickknowledge.com\/exam\/general-science\/\">General Science<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/study-materials\/\">Study Materials<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/current-affairs\/\">Current Affairs<\/a>, <a href=\"https:\/\/thequickknowledge.com\/exam\/practice-questions\/\">Practice Questions<\/a>,\u00a0<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Matter, Atoms &amp; Elements (Metals &amp; Non-Metals) matter, which is defined as anything that has mass and occupies space. Everything around us \u2013 air, water, food, stones, stars, plants \u2013 is considered matter. Modern science, however, classifies matter based on physical and chemical properties. Key Physical Properties: Matter is made up of particles, these particles [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"no-sidebar","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"disabled","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[137],"tags":[138],"class_list":["post-3463","post","type-post","status-publish","format-standard","hentry","category-general-science","tag-general-science-notes"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3463","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/comments?post=3463"}],"version-history":[{"count":11,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3463\/revisions"}],"predecessor-version":[{"id":3485,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/posts\/3463\/revisions\/3485"}],"wp:attachment":[{"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/media?parent=3463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/categories?post=3463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thequickknowledge.com\/exam\/wp-json\/wp\/v2\/tags?post=3463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}