Class 10 Science Chapter 3 Metals and Non-metals
Welcome to Class 10 Science Chapter 3 Metals and Non-metals. This chapter is an important part of Class 10 Science and helps students understand the physical and chemical properties of metals and non-metals. It is a key chapter for school examinations, board exams, and other competitive tests.
In this chapter, students will learn about the characteristics of metals and non-metals, their reactions with oxygen, water, acids, and salts, the reactivity series, extraction of metals, corrosion, and methods to prevent corrosion. The chapter also explains the uses of different metals and non-metals in everyday life, making it easier to connect scientific concepts with practical applications.
The study material is written in simple and easy language, allowing students to understand each concept clearly. It is useful for learning important topics, revising key points, and preparing confidently for examinations. A strong understanding of this chapter will also help students in higher-level Chemistry.
Whether you are preparing for class tests, annual examinations, or board exams, Class 10 Science Chapter 3 Metals and Non-metals will help you strengthen your concepts and improve your performance in Science.
Class 10 Science Chapter 3 Metals and Non-metals
Selected Questions &Answers
Q. What is meant by the malleability of metals?
Ans: A metal can be beaten into thin sheets with a hammer. This property is called malleability of metals.
Q. What is your comment on the solubility of ionic compounds?
Ans: Ionic compounds are soluble in water but insoluble in solvents like kerosene and petrol.
Q. What is calcination?
Ans: Heating carbonate ores at high temperature in a limited supply of air to convert them into metal oxides is called calcination.
Q. Write two properties of non-metals.
Ans: Two properties of non-metals are-
(a) Non-metals do not have lustre.
(b) Non-metals are not malleable.
Q. Name one metal and one non-metal which are liquid at room temperature.
Ans: Mercury (metal) and bromine (non-metal).
Q. Write one allotrope of carbon.
Ans: Graphite.
Q. Give one example of an alkali metal.
Ans: Lithium or sodium.
Q. Name a metal that can be cut easily with a knife.
Ans: Lithium or sodium.
Q. Name two metal oxides that react easily with water.
Ans: Sodium oxide and potassium oxide.
Q. What is produced when magnesium reacts with hot water?
Ans: Magnesium hydroxide and hydrogen gas.
Q. Name two metals that do not react with cold or hot water.
Ans: Lead and copper.
Q. Name two metals that react with steam.
Ans: Aluminium and iron.
Q. Why does nitric acid not produce hydrogen gas when it reacts with metals?
Ans: Nitric acid is an oxidizing agent. It oxidizes the hydrogen formed into water and itself gets reduced to nitrogen compounds.
Q. Why do ionic compounds have high melting and boiling points?
Ans: Because of the strong electrostatic forces of attraction between ions.
Q. Which metals do not corrode easily?
Ans: Noble metals.
Q. What is an alloy?
Ans: A homogeneous mixture of two metals or a metal and a non-metal is called an alloy.
Q. Describe two methods to prevent rusting of iron.
Ans: Two methods to prevent rusting of iron are-
(a) Painting the surface of iron.
(b) Galvanizing (coating with zinc).
Q. Write one difference between metals and non-metals.
Ans: Metals are generally found in the solid state, whereas non-metals are often found in the gaseous state.
Q. Which of the following metals reacts vigorously with oxygen? HSLC’17
(a) Na
(b) Fe
(c) Cu
(d) Ag
Ans: (a) Na
Q. Which of the following metals reacts most vigorously? HSLC ’16
(a) Al
(b) Fe
(c) Na
(d) Ca
Ans: (c) Na
Q. Identify the non-metal from the following elements. HSLC ’15
(a) Sodium
(b) Aluminium
(c) Chlorine
(d) Boron
Ans: (c) Chlorine
Q. Give examples of metals that—
(i) Are liquid at room temperature
(ii) Can be cut with a knife
(iii) Are the best conductors of heat
(iv) Are poor conductors of heat
Ans:
(i) Mercury
(ii) Sodium
(iii) Copper
(iv) Lead
Q. Write the difference between minerals and ores with an example. HSLC ’17
Ans: Minerals are naturally occurring substances in the earth’s crust in the form of elements or compounds. Ores are those minerals from which metals can be profitably extracted.
Example: Bauxite is a mineral of aluminium and also its ore.
Q. Write the chemical equations for the following reactions. HSLC ’15
(a) Reaction of iron with steam
(b) Reaction of calcium with water
Ans:
(a) 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
(b) Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g)
Q. Explain malleability and ductility.
Ans: The property by which a substance can be beaten into thin sheets is called malleability. The property by which a substance can be drawn into wires is called ductility.
Q. Why is sodium stored in kerosene oil? HSLC ’15
Ans: Sodium is highly reactive and reacts with oxygen and water in air, producing heat. Therefore, it is stored in kerosene oil.
Q. Name a metal that is liquid at room temperature. HSLC ’17
Ans: Mercury.
Q. What gas is produced when an active metal reacts with dilute hydrochloric acid? Write the equation for the reaction of iron with dilute sulphuric acid.
Ans: Hydrogen gas is produced.
Fe + H₂SO₄ → FeSO₄ + H₂
Q. Why do ionic compounds have high melting points?
Ans: Due to strong electrostatic forces between ions, a large amount of heat energy is required to separate them.
Q. Define the following. HSLC ’20
(i) Mineral
(ii) Ore
(iii) Gangue
Ans:
(i) Mineral: Naturally occurring substances in the earth’s crust in the form of elements or compounds.
(ii) Ore: Substances from which metals can be extracted economically.
(iii) Gangue: Unwanted impurities present in ores.
Q. Name two metals found in the free state in nature.
Ans: Gold and silver.
Q. Which chemical method is used to extract metals from oxides? HSLC’20
Ans: Reduction method.
Q. Which metals do not corrode easily?
Ans: Gold and platinum.
Q. What is an alloy?
Ans: A homogeneous mixture of two or more metals or a metal and a nonmetal.
Q. In which of the following will a displacement reaction occur?
(a) NaCl solution and copper
(b) MgCl2 solution and aluminium
(c) FeSO4 solution and silver
(d) AgNO3 solution and copper
Ans: (d) AgNO3 solution and copper
Q. Which method is suitable to prevent rusting of an iron frying pan?
(a) Applying grease
(b) Using oil
(c) Coating with zinc
(d) All of the above
Ans: (d) All of the above
Q. An element reacts with oxygen to form a compound with a high melting point which is soluble in water. The element is—
(a) Calcium
(b) Carbon
(c) Silicon
(d) Iron
Ans: (a) Calcium
Q. Why are food containers coated with tin and not zinc?
(a) Zinc is costlier than tin
(b) Zinc has higher melting point
(c) Zinc is more reactive than tin
(d) Zinc is less reactive than tin
Ans: (c) Zinc is more reactive than tin
Q. You are given a hammer, a battery, some wires and a switch. HSLC’15, ’19
(a) How will you identify metals and non-metals?
(b) Evaluate the usefulness of these tests.
Ans:
(a) By hammering, metals can be flattened, whereas non-metals break. By connecting with a battery, metals conduct electricity, but non-metals do not.
(b) The hammer test is more useful because metals are malleable, whereas non-metals are not.
Q. Name two metals that displace hydrogen from dilute acids and two that do not.
Ans: Metals that displace hydrogen: Sodium, Calcium; Metals that do not: Copper, Silver
Q. In electrolytic refining of a metal M, what should be taken as anode, cathode and electrolyte?
Ans: Impure metal M as anode, pure metal M as cathode, and a solution of its salt as electrolyte.
Q. A student heats sulphur and collects the gas produced.
(a) How does the gas react with (i) dry litmus paper and (ii) moist litmus paper?
(b) Write the balanced equation.
Ans:
(a) (i) No reaction with dry litmus.
(ii) Turns moist litmus red.
(b) SO₂ + H₂O → H₂SO₃
Q. Describe two methods to prevent rusting of iron.
Ans:
(i) Painting the surface
(ii) Coating with zinc
Q. What type of oxides are formed when non-metals react with oxygen?
Ans: Acidic oxides.
Q. Give reasons. HSLC ’15
(a) Platinum, gold and silver are used for making jewellery.
(b) Sodium, potassium and lithium are stored in oil.
(c) Aluminium is used for making cooking utensils despite being reactive.
(d) Carbonate and sulphide ores are converted into oxides during extraction.
Ans:
(a) They are lustrous, malleable, ductile and resist corrosion.
(b) They are highly reactive and react with air and moisture.
(c) Aluminium forms a protective oxide layer and is a good conductor of heat.
(d) Extraction of metals from oxides is easier.
Q. Why are copper vessels cleaned with lemon or tamarind? HSLC’20
Ans: The green coating is copper carbonate, which dissolves in acids present in lemon or tamarind.
Q. Write differences between metals and non-metals based on chemical properties.
Ans:
1. Metals react with non-metals, whereas non-metals react with both metals and non-metals.
2. Metals form basic oxides, non-metals form acidic oxides.
3. Metal hydrides are ionic, non-metal hydrides are covalent.
Q. Why is copper used to make hot water tanks instead of steel?
Ans: Copper is a better conductor and does not corrode easily compared to steel.
Q. What is metallic lustre?
Ans: The shiny appearance of a pure metal surface is called metallic lustre.
Q. Write four properties each of metals and non-metals.
Ans: Properties of metals:
(a) Lustrous
(b) High melting and boiling points
(c) Good conductors of electricity
(d) Malleable and ductile Properties of non-metals:
(a) Poor conductors of heat
(b) Covalent hydrides
(c) Generally low melting points
(d) Poor conductors of electricity
Q. Write the names of the alloys of copper and zinc, copper and tin, and lead and tin. HSLC ’19
Ans: The alloy of copper and zinc is brass.
The alloy of copper and tin is bronze.
The alloy of lead and tin is solder.
Q. What are amphoteric oxides? Give examples.
Ans: Oxides that react with both acids and bases to produce salt and water are called amphoteric oxides.
Examples: Aluminium oxide, zinc oxide.
Q. Give reasons.
(a) Aluminium foil is used for wrapping food materials.
(b) Immersion rods used for heating liquids are made of metallic substances.
Ans:
(a) Aluminium can be easily beaten into thin sheets. Therefore, it is used for wrapping food.
(b) Metals are good conductors of heat and electricity. Therefore, immersion rods are made of metals.
Q. What will happen when—
(a) Dilute sulphuric acid is poured on a copper plate.
(b) An iron nail is placed in copper sulphate solution.
Write the appropriate equations.
Ans:
(a) No reaction occurs when dilute sulphuric acid is poured on copper.
(b) Iron displaces copper from copper sulphate solution.
Fe + CuSO₄ → FeSO₄ + Cu
Q. Name two metals that do not react with water.
Ans: Silver and gold.
Q. What are ionic or electrovalent compounds? Give examples.
Ans: Compounds formed by transfer of electrons from a metal to a nonmetal are called ionic or electrovalent compounds.
Examples: NaCl, CaCl₂, CaO, MgCl₂.
Q. What are metalloids? Give an example.
Ans: Elements that show properties of both metals and non-metals are called metalloids. Example: Silicon.
Q. Explain corrosion with an example. HSLC ’15
Ans: When a metal is affected by substances like moisture, air, or acids present in the environment, it is called corrosion. As a result, the properties of the metal deteriorate.
Example: The reddish-brown coating (rust) on iron.
Q. Why should a magnesium ribbon be cleaned before burning in air? HSLC ’19
Ans: Magnesium reacts with oxygen in air and forms a layer of magnesium oxide on its surface. This layer should be removed before burning.
Q. What type of oxides are formed when non-metals react with oxygen? HSLC ’17
Ans: Acidic oxides are formed.
Q. An element reacts with oxygen to form a compound with high melting point which is soluble in water. Identify the element. HSLC ’19
(a) Calcium
(b) Carbon
(c) Silicon
(d) Iron
Ans: (a) Calcium
Q. A metallic compound reacts with dilute hydrochloric acid producing effervescence. The gas extinguishes a burning candle. HSLC ’18
(a) Name the gas.
(b) If one of the products is calcium chloride, write the balanced equation.
Ans:
(a) Carbon dioxide (CO₂)
(b) CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂
Q. What are amphoteric oxides? Give two examples. HSLC ’19
Ans: Metal oxides that react with both acids and bases to produce salt and water are called amphoteric oxides.
Examples: Aluminium oxide (Al2O3) and zinc oxide (ZnO).
Q. A student heats sulphur and collects the gas produced. How does the gas react with— HSLC ’19
(a) Dry litmus paper
(b) Moist litmus paper
Ans:
(a) No reaction with dry litmus paper.
(b) It reacts with moist litmus to form sulphurous acid and turns blue litmus red.
Q. Name one metal found in free state in nature. HSLC ’17
Ans: Gold.
Q. What is the ductility of a metal? HSLC ’19
Ans: The property by which a metal can be drawn into wires is called ductility.
Q. Mention two methods to prevent rusting of iron. HSLC ’19
Ans: Painting and applying oil/grease.
Q. What happens when zinc is added to iron sulphate solution? Write the reaction. HSLC ’18
Ans: Zinc displaces iron from iron sulphate solution, forming zinc sulphate.
Zn + FeSO₄ → ZnSO₄ + Fe
Q. What is meant by refining of metals? Which method is commonly used? What is anode mud? HSLC ’18
Ans: The process of removing impurities from a metal to make it usable is called refining of metals. The commonly used method is electrolytic refining. During electrolytic refining, impurities like gold, silver, and platinum settle at the bottom as sludge, called anode mud.
Multiple Choice Questions (MCQ)
Q. In which of the following cases will a displacement reaction occur?
(a) Solution of NaCl and copper
(b) Solution of MgCl₂ and aluminium metal
(c) Solution of FeSO₄ and silver metal
(d) Solution of AgNO₃ and copper metal
Ans: (d) Solution of AgNO₃ and copper metal
Q. The ore of zinc is—
(a) Hematite
(b) Zinc blende
(c) Bauxite
(d) Copper pyrites
Ans: (b) Zinc blende
Q. Select the metalloid from the following elements.
(a) Sodium
(b) Aluminium
(c) Chlorine
(d) Boron
Ans: (d) Boron
Q. Which of the following metals does not react with either hot or cold water?
(a) Sodium
(b) Aluminium
(c) Potassium
(d) Calcium
Ans: (b) Aluminium
Q. Which of the following metals reacts vigorously with cold water?
(a) Al
(b) Fe
(c) Na
(d) Ca
Ans: (d) Ca
Q. When metals react with nitric acid, hydrogen gas is not evolved because—
(a) Nitric acid is a reducing agent
(b) Nitric acid is an oxidizing agent
(c) Nitric acid is a strong acid
(d) Nitric acid is a weak acid
Ans: (b) Nitric acid is an oxidizing agent
Q. Which of the following metals reacts vigorously with oxygen?
(a) Na
(b) Fe
(c) Cu
(d) Ag
Ans: (a) Na
Q. The substances found in the earth’s crust in the form of elements or compounds are called—
(a) Gangue
(b) Minerals
(c) Metalloids
(d) Ores
Ans: (b) Minerals
Q. The chemical formula of cinnabar is—
(a) HgO
(b) MgO
(c) NaO
(d) HgS
Ans: (d) HgS
Q. An element reacts with oxygen to form a compound with a high melting point which is soluble in water. The possible element is—
(a) Calcium
(b) Carbon
(c) Silicon
(d) Iron
Ans: (a) Calcium
Q. Which of the following is found in the free state in nature?
(a) Na
(b) K
(c) Au
(d) Mg
Ans: (c) Au
Q. Which method is used to prevent rusting of iron?
(a) Using grease
(b) Using oil
(c) Applying paint
(d) All of the above
Ans: (d) All of the above
Q. Which method is suitable to prevent an iron frying pan from rusting?
(a) Using grease
(b) Using paint
(c) Coating with zinc
(d) All of the above
Ans: (d) All of the above
Q. The alloy of lead and tin is—
(a) Solder
(b) Hematite
(c) Brass
(d) Tungsten
Ans: (a) Solder
Q. Which type of metals are obtained in pure form by electrolysis?
(a) Less reactive metals
(b) Moderately reactive metals
(c) Highly reactive metals
(d) All of the above
Ans: (c) Highly reactive metals
Q. Food containers are coated with tin and not with zinc because—
(a) Zinc is more expensive than tin
(b) Zinc has higher melting point than tin
(c) Zinc is more reactive than tin
(d) Zinc is less reactive than tin
Ans: (c) Zinc is more reactive than tin
Q. Which ore is concentrated by the froth flotation method?
(a) Hematite
(b) Zinc blende
(c) Bauxite
(d) Horn silver
Ans: (b) Zinc blende
Q. Where is sodium metal stored?
(a) In kerosene oil
(b) In water
(c) In salt solution
(d) All of the above
Ans: (a) In kerosene oil
