This PSEB 10th Class Science Notes Chapter 3 Metals and Non-metals will help you in revision during exams.
PSEB 10th Class Science Notes Chapter 3 Metals and Non-metals
→ Iron, Copper, Aluminium, Magnesium, Sodium, Lead, Zinc, etc. Metals are easily available.
→ Metals have shining surfaces, called metallic luster.
→ Sodium metal can be cut by a knife.
→ Metals are usually hard and can be beaten into thin sheets and drawn into wires.
→ Gold is most ductile that is why from one gram of gold, a 2km long wire can be drawn.
→ Metals are good conductors of heat.
→ Malleability and ductility are two important properties of metals.
→ Lead and mercury are bad conductors whereas silver and copper are very good conductors.
→ Metals have sonorous properties.
→ Carbon, Sulphur, Iodine, Oxygen, Hydrogen etc. are non-metals.
→ Bromine is a non-metal which exists in liquid form.
→ Mercury exists in liquid form at room temperature.
→ Gallium and Cesium have a very low melting point, which melts even when placed on our palms.
→ Iodine is non-metal but is lustrous.
→ Lithium, Sodium, Potassium are alkali metals and are very soft, they can be cut with a knife.
→ Most of the non-metals produce acidic oxides when dissolved in water.
→ Magnesium burns in the air with dazzling white flame.
→ On heating copper, it changes to black coloured copper oxide.
→ Those metal oxides that react with acid as well as with bases and produce salt and water in both cases are called amphoteric oxides.
→ Gold and silver do not react with oxygen even on heating.
→ Aqua regia is a fresh mixture of concentrated HCl and Concentrated HNO3 in the ratio 3 : 1.
→ Aqua regia can dissolve in Gold and platinum.
→ Reactivity series is a list of metals in which metals are arranged in decreasing activity.
→ Noble gases have completely filled valence shells and thus are less reactive.
→ Helium, Neon, Argon are Noble gases.
→ Compounds formed by the transfer of electrons from metals to non-metals are called ionic or electrovalent compounds.
→ Ionic compounds are solid and hard. They have high melting and boiling point. They can conduct electricity.
→ Earth’s crust is the main source of metals.
→ The elements or compounds which occur naturally in the earth’s crust are called minerals.
→ Some of the minerals from which extraction of metals is easy and profitable are called ores.
→ Gold, silver, platinum, and copper are at the bottom of the reactivity series and are least reactive, and are found in a free state.
→ Zinc, Iron, lead are moderately reactive and are found in the form of oxide, sulphide, or carbonate in the Earth’s crust.
→ Sodium, Potassium, calcium, Magnesium, Aluminium, etc. are at the top of the reactivity series and are so reactive that they are never found in a free state in nature.
→ Ores are contaminated with impurities like soil, sand, etc. known as gangue.
→ If sulphide ores are heated in excess air, they convert to oxides. This is called roasting.
→ Carbonate ores are converted into oxides by heating them strongly in a limited supply of air. This is known as calcination.
→ The reaction of iron oxide with aluminium is called the thermit reaction.
→ Electrolytic refining is used to purify metals.
→ Silver articles become black after some time when exposed to air due to the formation of a coating of silver sulphide.
→ Copper gains a green coating of basic copper carbonate due to corrosion when left in air for a long time CuCO3.Cu(OH)2.
→ Iron acquires a brown coating called rust.
→ Corrosion is prevented by greasing, painting, galvanising, chrome plating, anodizing, etc.
→ The homogeneous mixture of two or more two metals is called an alloy.
→ Pure Gold, which is 24-carat gold, which is very soft.
→ For making ornaments silver or copper is mixed with gold.
→ Generally, 22-carat gold is used for making ornaments. If alloy contains one of its constituents as mercury (Hg) it is called amalgam.
→ Alloy Bronze is a bad conductor of electricity.
→ Ductility: It is a property of metals by virtue of which long wires can be drawn. Electric wire is an example of ductility.
→ Malleability: It is a property of metals by virtue of which metals can be beaten into thin sheets.
→ Conductivity: Metals allow the passage of heat and electricity through them, this is called conductivity.
→ Mineral: Substances from which metals can be extracted are called minerals. Metals can be extracted from minerals by different methods.
→ Metallurgy: To extract metals from their ores and purify them for use is called metallurgy.
→ Ore: Those minerals from which metal extraction is easy and profitable are called ores.
→ Gangue: Ores mined from the earth are contaminated with impurities such as soil, sand, etc. are called gangue.
→ Roasting: The process of converting enriched ore in the excess of air is called roasting.
→ Reduction: It is a process of obtaining metals from compounds.
→ Purification: It is a process of obtaining pure metal from impure metal.
→ Alloy: Mixture of a metal with other metal or non-metal in the called alloy.
→ Allotropy: A property by virtue of which non-metals exist in different forms is called allotropy.
→ Vulcanization: Mixing sulphur with natural rubber is called vulcanization and such rubber is called vulcanized rubber.
→ Slag: It is a substance that is obtained when gangue and smelter are together.
→ Smelter: It is a substance which is used to separate gangue in the form of liquid from an impure metal.
→ Calcination: It is a process of heating ore in the limited supply of air. Ore becomes porous in this process.
→ Smelting: It is a process to extract an element from its ore using heat and a reduction agent.
→ Metals: Metals are those elements which lose electrons to form positive ions.
→ Non-Metals: Non-Metals are those elements which gain electrons to form negative ions.
→ Amalgam: When one of the constituents of an alloy is mercury it is called an alloy.
→ Corrosion: The effect of air, water, or any other substance on the surface of the metal is called corrosion.
→ Strategic metals: These are the metals that are important for the economy and safety of the country are strategic metals.
→ Electropositive elements: Those elements which lose electrons to form positive ions are known as electropositive elements: Metals belong to this category.
→ Electronegative elements: Those elements which gain electrons to form negative ions are known as electronegative elements. Non-metals belong to this category.
→ Reactivity series of metals: Arrangement of metals in a column in decreasing reactivity of metals is called reactivity series of metals.
→ Displacement reactions: The replacement of less reactive metal by more reactive metal from its salt in a reaction is called displacement reaction.
→ Catalyst: These are substances that do not take part in a reaction but can increase or decrease the rate of reaction are called catalysts.
→ Promotor: Substances that increase the performance of catalysts are called promotors.