Class 10 Science Chapter 3 Metals and Non-Metals NCERT Solutions 2026 PDF Download
📝 Introduction
Metals and Non-Metals explores the fundamental building blocks of materials. You will learn to classify elements based on physical properties (like luster, malleability) and chemical properties (reaction with oxygen, water, and acids). A key focus of this chapter is the Reactivity Series, which helps predict displacement reactions. You will also dive into the formation of Ionic Compounds through electron transfer and study Metallurgy—the process of extracting pure metals from ores. Finally, the chapter covers Corrosion and the science of Alloys.
🔑 Key Concepts & Formulas
- Physical Properties: Metals are malleable, ductile, sonorous, and good conductors. Non-metals are brittle and poor conductors (except Graphite).
- Amphoteric Oxides: Metal oxides that react with both acids and bases (e.g., Al₂O₃, ZnO).
- Ionic Bond: Strong electrostatic force formed by the transfer of electrons from a metal to a non-metal.
- Metallurgy:
- Roasting: Heating sulphide ores in excess air (2ZnS + 3O₂ → 2ZnO + 2SO₂).
- Calcination: Heating carbonate ores in limited air (ZnCO₃ → ZnO + CO₂).
- Thermite Reaction: Reaction of Iron(III) oxide with Aluminium powder to produce molten iron (used to join railway tracks).
- Alloys: Homogeneous mixture of two or more metals (e.g., Brass = Cu + Zn, Bronze = Cu + Sn).
📚 Part 1: NCERT Solutions (In-Text & Exercises)
Q1: Give an example of a metal which: (i) is liquid at room temperature (ii) can be easily cut with a knife (iii) is the best conductor of heat (iv) is a poor conductor of heat.
Ans:
(i) Liquid at room temp: Mercury
(ii) Cut with a knife: Sodium or Potassium
(iii) Best conductor: Silver
(iv) Poor conductor: Lead or Mercury
Q2: Why are sodium and potassium kept immersed in kerosene oil?
Ans: Sodium and Potassium are highly reactive metals. If kept in the open, they react vigorously with Oxygen and moisture in the air and catch fire. To prevent this accidental fire, they are kept immersed in kerosene oil to cut off contact with air.
Q3: Define the terms: (i) Mineral (ii) Ore (iii) Gangue.
Ans:
- Mineral: Naturally occurring elements or compounds in the earth's crust.
- Ore: A mineral that contains a high percentage of a particular metal which can be extracted profitably.
- Gangue: The earthly impurities (sand, soil, silt) present along with the mineral in an ore.
Q4: What are amphoteric oxides? Give two examples.
Ans: Metal oxides that show both acidic as well as basic behaviour are called amphoteric oxides. They react with both acids and bases to produce salt and water.
Examples: Aluminium Oxide (Al₂O₃) and Zinc Oxide (ZnO).
Q5: Why do ionic compounds have high melting points?
Ans: Ionic compounds are formed by strong electrostatic forces of attraction between oppositely charged ions (cations and anions). A considerable amount of energy is required to break these strong inter-ionic forces, resulting in high melting and boiling points.
Q6: Differentiate between Roasting and Calcination.
Ans:
- Roasting: Used for Sulphide ores. The ore is heated in the presence of excess air. (Ex: 2ZnS + 3O₂ → 2ZnO + 2SO₂)
- Calcination: Used for Carbonate ores. The ore is heated in limited air or absence of air. (Ex: ZnCO₃ → ZnO + CO₂)
Q7: Show the formation of Na₂O and MgO by the transfer of electrons.
Ans:
- Na₂O: Two Sodium atoms (2,8,1) each lose 1 electron to become 2Na⁺. One Oxygen atom (2,6) gains these 2 electrons to become O²⁻.
- MgO: Magnesium (2,8,2) loses 2 electrons to become Mg²⁺. Oxygen (2,6) gains 2 electrons to become O²⁻.
Q8: Why is copper used to make hot water tanks and not steel (an alloy of iron)?
Ans: Copper is a better conductor of heat than steel. More importantly, Copper does not react with water (even steam), whereas Iron (in steel) reacts with steam to form rust, which corrodes the tank.
Q9: Explain the electrolytic refining of Copper.
Ans: In this process:
- Anode: Impure copper block.
- Cathode: Thin strip of pure copper.
- Electrolyte: Acidified copper sulphate solution.
⚡ Part 2: 15 Extra Practice Questions (PYQ Style)
Short Answer Type Questions
Q1: What is Aqua Regia? Why is it unique?
Ans: Aqua Regia (Royal Water) is a freshly prepared mixture of concentrated Hydrochloric Acid and concentrated Nitric Acid in the ratio of 3:1. It is unique because it can dissolve noble metals like Gold and Platinum, which do not dissolve in individual acids.
Q2: Why does calcium float when treated with water?
Ans: Calcium reacts with water to form Calcium Hydroxide and Hydrogen gas. The bubbles of Hydrogen gas formed stick to the surface of the metal, causing it to float on the water surface.
Q3: Write chemical equations for the reaction of Iron with steam.
Ans: Iron does not react with cold or hot water but reacts with steam to form Iron(II,III) oxide and hydrogen.
3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
Q4: What is Anodising? How is it useful?
Ans: Anodising is a process of forming a thick oxide layer of Aluminium. When Al is exposed to air, it develops a thin oxide layer that protects it from corrosion. Anodising makes this layer thicker (using electrolysis), making the metal highly resistant to corrosion and suitable for dyeing.
Q5: Explain the Thermite Reaction with an equation. Mention its use.
Ans: It is the reaction between Iron(III) Oxide and Aluminium powder. It is highly exothermic, producing molten iron.
Fe₂O₃(s) + 2Al(s) → 2Fe(l) + Al₂O₃(s) + Heat
Use: To join railway tracks or cracked machine parts.
Long Answer Type Questions
Q6: A metal 'X' does not react with cold water but reacts with hot water to form a hydroxide. Metal 'Y' does not react with water at all but reacts with steam to form an oxide. Identify X and Y.
Ans:
- Metal X is Magnesium (Mg). It reacts with hot water to form Mg(OH)₂.
- Metal Y is Iron (Fe) or Zinc (Zn) or Aluminium (Al). These react with steam to form oxides (e.g., Fe₃O₄).
Q7: Explain the formation of Magnesium Chloride (MgCl₂) with the help of electron dot structure.
Ans: Magnesium (Z=12) has configuration 2,8,2. It loses 2 electrons to form Mg²⁺. Chlorine (Z=17) has configuration 2,8,7. It needs 1 electron.
One Mg atom donates its 2 valence electrons, one to each of two Chlorine atoms. This forms one Mg²⁺ ion and two Cl⁻ ions, creating the ionic compound MgCl₂.
Q8: Give reasons: (a) Platinum, gold and silver are used to make jewellery. (b) Aluminium is a highly reactive metal, yet it is used to make cooking utensils.
Ans:
(a) They are noble metals at the bottom of the reactivity series. They do not corrode, stay shiny (lustrous), and are malleable/ductile.
(b) Aluminium forms a thin, non-reactive layer of Aluminium Oxide (Al₂O₃) on its surface which protects it from further corrosion. It is also a good conductor of heat and is lightweight.
Competency Based Questions
Q9: Carbon cannot reduce the oxides of Sodium, Magnesium, Calcium, or Aluminium. Why? How are these metals obtained?
Ans: These metals are highly reactive and have a higher affinity for oxygen than carbon does. Therefore, carbon cannot remove the oxygen from their oxides. These metals are obtained by Electrolytic Reduction of their molten chlorides.
Q10: What happens when Zinc granules are treated with: (i) H₂SO₄ (ii) NaOH solution. Write equations.
Ans: Zinc is amphoteric (reacts with acid and base).
(i) With Acid: Zn + H₂SO₄ → ZnSO₄ + H₂
(ii) With Base: Zn + 2NaOH → Na₂ZnO₂ (Sodium Zincate) + H₂
Q11: What is an Amalgam?
Ans: An alloy in which one of the metals is Mercury is known as an Amalgam. Example: Sodium Amalgam (Na-Hg), Zinc Amalgam.
Q12: Differentiate between a mineral and an ore.
Ans: All ores are minerals, but not all minerals are ores. A mineral is any naturally occurring substance containing a metal. An ore is a specific mineral from which that metal can be extracted profitably and conveniently.
Q13: Name the constituents of: (i) Brass (ii) Bronze (iii) Solder.
Ans:
(i) Brass: Copper + Zinc
(ii) Bronze: Copper + Tin
(iii) Solder: Lead + Tin (Low melting point, used for welding electrical wires).
Q14: Why do ionic compounds conduct electricity in molten state but not in solid state?
Ans: Conductivity requires free movement of ions. In the solid state, ions are held firmly in fixed positions by strong electrostatic forces. In the molten state (or aqueous solution), heat overcomes these forces, allowing ions to move freely and conduct electricity.
Q15: What is Galvanisation?
Ans: Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of Zinc. Zinc is more reactive than iron, so it corrodes preferentially, protecting the iron underneath (Sacrificial protection).