CBSE Class 10 Science Notes Chapter 3 Metals and Non-metals

Here are concise notes for CBSE Class 10 Science Chapter 3: Metals and Non-metals:

Physical Properties: Lustrous, malleable, ductile, good conductors of heat/electricity, high melting points.
Chemical Properties:
- Reaction with oxygen: Forms metal oxides (e.g., $4Na + O_2 → 2Na_2O$ ).
- Reaction with water: Produces metal hydroxides and hydrogen.
- Reaction with acids: Forms salt and releases hydrogen gas.
- Reactivity series: Determines reactivity; e.g., K > Na > Ca > Mg > Zn > Fe > Cu > Ag.

Physical Properties: Non-lustrous, brittle, poor conductors, low melting points.
Chemical Properties:
- Reaction with oxygen: Forms acidic or neutral oxides.
- Do not react with acids to release hydrogen.

Mixtures of metals or metals with non-metals; e.g., Brass (Cu + Zn), Steel (Fe + C).

Most Important Science Class 10 Questions Answers 2025

Answer: Metals have free electrons in their outer shells that move freely and conduct electricity.

Answer: $Zn + 2HCl \rightarrow ZnCl_2 + H_2$ Zinc reacts with HCl to form zinc chloride and release hydrogen gas.

Answer: Corrosion is the gradual deterioration of a metal by its reaction with the environment (e.g., rusting).
Prevention:
- Painting
- Galvanization
- Electroplating
- Using alloys

Answer:
1. Concentration: Removal of impurities from ore.
2. Reduction: Metal oxides are reduced to metals.
3. Refining: Purification of the extracted metal.

Answer: Sodium is highly reactive and reacts vigorously with water and air. Storing in kerosene prevents unwanted reactions.

Here are some multiple-choice questions (MCQs) based on CBSE Class 10 Science Chapter 3: Metals and Non-Metals:

Which of the following metals is the most reactive?
a) Copper
b) Zinc
c) Potassium
d) Iron
Answer: c) Potassium
What is the formula of rust?
a) FeO
b) Fe₂O₃
c) Fe₂O₃·xH₂O
d) Fe₃O₄
Answer: c) Fe₂O₃·xH₂O
Which non-metal is a good conductor of electricity?
a) Sulfur
b) Carbon (Graphite)
c) Phosphorus
d) Iodine
Answer: b) Carbon (Graphite)
Which of the following is an amphoteric oxide?
a) Al₂O₃
b) CO₂
c) MgO
d) SO₂
Answer: a) Al₂O₃
The process of coating a layer of zinc on iron to prevent rusting is called:
a) Galvanization
b) Electroplating
c) Anodizing
d) Alloying
Answer: a) Galvanization
Which method is used to extract highly reactive metals like sodium and potassium?
a) Reduction of carbon
b) Electrolysis
c) Heating in the air
d) Smelting
Answer: b) Electrolysis
Which property is NOT true for ionic compounds?
a) High melting point
b) Conduct electricity in solid state
c) Soluble in water
d) Form crystalline solids
Answer: b) Conduct electricity in solid state
Which metal reacts with water at room temperature to form hydrogen gas?
a) Zinc
b) Sodium
c) Aluminium
d) Copper
Answer: b) Sodium
An alloy of copper and zinc is called:
a) Steel
b) Brass
c) Bronze
d) Solder
Answer: b) Brass
Which of the following will not corrode?
a) Copper
b) Aluminium
c) Platinum
d) Iron
Answer: c) Platinum