Define an atom.

Important Questions on Atoms and Molecules

MEDIUM

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>Let us answer these:>Q 2

In what unit the radius of an atom is usually expressed?

MEDIUM

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>Let us answer these:>Q 3

What is a molecule? Explain with example.

MEDIUM

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>Let us answer these:>Q 4

What is the difference between the molecule of an element and the molecule of a compound? Illustrate with one example each.

HARD

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>Let us answer these:>Q 5

What is meant by atomicity? Give example.

MEDIUM

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>Let us answer these:>Q 6

Define atomic mass. What is meant by saying that atomic mass of Calcium is $40$.

HARD

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>EXERCISES>Q 1

What are the postulates of Dalton's atomic theory?

HARD

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>EXERCISES>Q 2

$3 \mathrm{g}$ of Magnesium combines with $2 \mathrm{g}$ of Oxygen to produce $5 \mathrm{g}$ of Magnesium oxide compound. If $6 \mathrm{g}$ of Magnesium is allowed to react with $20 \mathrm{g}$ of Oxygen, what mass of Magnesium oxide will be produced in the reaction? Name the law which governs your answer.

HARD

9th Manipur Board

IMPORTANT

Science for Class 9>Chapter 3 - Atoms and Molecules>EXERCISES>Q 3

Distinguish between atom and a molecule of an element.