HARD
7th CBSE
IMPORTANT
Earn 100

Differentiate between an element, a compound, and a mixture. Give atleast one relevant example for each.

Important Questions on Chemicals and Chemical Changes

MEDIUM
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 2
What is atomicity? Give one example each for monoatomic, diatomic and tetra atomic elements.
HARD
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 3
Name all the elements present in the following compounds: SO2, PbCl2, BaOH2, LiF.
MEDIUM
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 4
Why do the cut surfaces of fruits and vegetables turn brown?
MEDIUM
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 5
Write a short note on crystallization.
HARD
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 1
Explain the process used for removing impurities from common salt.
MEDIUM
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 2

Represent the following using chemical symbols / formulae:

Two atoms of the element neon.

EASY
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 2

Represent the following using chemical symbol / formula:

A molecule of the element Nitrogen.

EASY
7th CBSE
IMPORTANT
NEW SCIENCE In Everyday Life>Chapter 4 - Chemicals and Chemical Changes>Exercises>Q 2

Represent the following using chemical symbol / formula:

A molecule of the compound Carbon dioxide.