In this Class 7 Science Curiosity Chapter 4 The World of Metals and Non-metals, we explore the amazing properties, uses, and reactions of metals and non-metals. You will learn how metals can be shiny, strong, and good conductors, while non-metals are often brittle, dull, and poor conductors.
Have you ever wondered what makes up the tools we use, the wires that carry electricity, or the air we breathe? Our world is made of many different materials, and two important types are metals and non-metals.
We’ll also discover how these materials behave with air and water, why some metals rust, and why others are used to make jewellery, utensils, and even electrical wires. You’ll perform fun activities to test properties like malleability, ductility, sonority, and conductivity—helping you understand how science connects to everyday life.
Class 7 Science Curiosity Chapter 4 Worksheet
Get ready to enter the fascinating world of materials that build, protect, and power our lives. Download our Science Class 7 Curiosity Chapter 4 worksheet and stay ahead in competition.
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Class 7 Science Worksheet Curiosity
Class 7th Science NCERT Solutions Curiosity
Chapter 4 The World of Metals and Non-metals Notes
- Elements are classified as metals and non-metals based on their properties.
- Examples of metals: Iron, Aluminium, Copper.
- Examples of non-metals: Sulphur, Carbon, Oxygen.
Physical Properties of Metals
- Lustrous (shiny) appearance.
- Hard and strong, with high density.
- Malleable: Can be beaten into sheets.
- Ductile: Can be drawn into wires.
- Good conductors of heat and electricity.
- Sonorous: Produce sound when struck.
- High melting and boiling points.
Physical Properties of Non-metals
- Dull appearance (except iodine).
- Brittle and non-malleable.
- Poor conductors of heat and electricity (except graphite).
- Low melting and boiling points.
Chemical Properties
Metals:
- React with oxygen to form metal oxides (usually basic).
- React with water to form metal hydroxide and hydrogen gas.
- React with acids to produce salt and hydrogen gas.
Non-metals:
- React with oxygen to form non-metal oxides (usually acidic).
- Generally do not react with water or acids.
Uses of Metals
- Iron: Construction, tools.
- Copper: Electrical wiring.
- Aluminium: Utensils, aircraft bodies.
- Gold, Silver: Jewellery.
Uses of Non-metals
- Oxygen: Respiration.
- Carbon: Fuel.
- Nitrogen: Fertilizers.
- Sulphur: Vulcanisation of rubber.
Class 7 Science Curiosity Chapter 4 Fill in the Blanks
- Metals are good __________ of heat and electricity.
- Non-metals are __________ conductors of electricity.
- Iron reacts with sulphur to form __________.
- A metal is __________ if it can be drawn into wires.
- __________ is a non-metal used in fertilizers.
Class 7 Science Curiosity Chapter 4 Question – Answer
Q1. What is ductility?
Ans: Ductility is the property of a metal to be drawn into wires.
Q2. Why is copper used in electrical wiring?
Ans: Because it is a good conductor of electricity.
Q3. Give an example of a metal that reacts with cold water.
Ans: Sodium reacts vigorously with cold water.
Q4. Why are non-metals not used for making utensils?
Ans: Because they are brittle and poor conductors of heat.
Q5. What do you understand by the term ‘sonorous’?
Ans: A material is sonorous if it produces a ringing sound when struck.
Science Class 7 Curiosity Chapter 4 MCQs
Q1. Which of the following is a metal?
a) Oxygen
b) Sulphur
c) Aluminium
d) Carbon
Q2. Which of the following is a good conductor of electricity?
a) Sulphur
b) Graphite
c) Phosphorus
d) Plastic
Q3. What is formed when iron reacts with sulphur?
a) Iron oxide
b) Iron sulphide
c) Iron chloride
d) Iron carbonate
Q4. Which metal is used to make utensils?
a) Gold
b) Aluminium
c) Sodium
d) Lead
Q5. Which gas is produced when a metal reacts with acid?
a) Oxygen
b) Carbon dioxide
c) Hydrogen
d) Nitrogen