Chapter 5: Changes Around Us Physical and Chemical — Online MCQ Test
SCIENCE · Grade 7 · CBSE(NCERT)
Practice Chapter 5: Changes Around Us Physical and Chemical with a free chapter-wise online MCQ test.
This chapter covers: Physical change Chemical change Reversible Irreversible Reaction Rusting Burning Melting Freezing Expansion.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 5: Changes Around Us Physical and Chemical — Important Questions & Answers
Which of the following is a physical change?
- A. Burning of paper
- B. Rusting of iron
- C. Melting of ice
- D. Cooking of food
Answer: C. Melting of ice
Melting of ice changes only the state of water and no new substance is formed. It is therefore a physical change.
Melting of ice changes only the state of water and no new substance is formed. It is therefore a physical change.
The process of changing water into ice is called:
- A. Melting
- B. Freezing
- C. Evaporation
- D. Expansion
Answer: B. Freezing
Freezing is the change of liquid water into solid ice on cooling.
Freezing is the change of liquid water into solid ice on cooling.
Which statement best describes a physical change?
- A. A new substance is formed
- B. Only shape, size, or state changes
- C. It is always permanent
- D. It cannot be reversed ever
Answer: B. Only shape, size, or state changes
In a physical change, only the form, size, or state of a substance changes and no new substance is formed.
In a physical change, only the form, size, or state of a substance changes and no new substance is formed.
Which of the following changes is the best example of a chemical change followed by an irreversible effect?
- A. Melting ice cream
- B. Rusting of a bicycle chain
- C. Stretching a spring
- D. Breaking a pencil
Answer: B. Rusting of a bicycle chain
Rusting forms a new substance and damages the metal permanently, so it is chemical and irreversible.
Rusting forms a new substance and damages the metal permanently, so it is chemical and irreversible.
A metal lid is very tight on a glass jar. The best way to open it is to place the lid in warm water because:
- A. The lid contracts more than the glass
- B. The lid expands on heating
- C. The glass melts slightly
- D. The water makes the lid rust
Answer: B. The lid expands on heating
Heating causes the metal lid to expand, making it easier to remove from the jar.
Heating causes the metal lid to expand, making it easier to remove from the jar.