EASY
7th CBSE
IMPORTANT
Earn 100

Explain with the help of examples the difference between an atom and a molecule.

Important Questions on Physical and Chemical Changes

MEDIUM
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 2
List four properties of compounds.
MEDIUM
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 3

Write the balanced equation for the following chemical reaction.

Calcium Ca combines with oxygen O2 to form calcium oxide CaO.
EASY
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 3

Write balanced chemical equation for the following chemical reaction:

aluminium+chlorine→aluminium chloride

MEDIUM
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 4

Define a physial change and list its characteristics. Give three examples of physical changes.

HARD
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 5
How will you prepare crystals of alum? Explain.
HARD
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 6
Define a chemical change and list its characteristics. Give three examples of chemical changes.
HARD
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 7
What is rusting of iron? How can it be prevented?
HARD
7th CBSE
IMPORTANT
New Science Ahead>Chapter 6 - Physical and Chemical Changes>Exercises>Q 8
Describe an experiment to prove that water and air are needed for rusting to occur.