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Quiz on Atoms and Molecules

Total questions: 14

Worksheet time: 7mins

Name
Class
Date
1.

Who first introduced the concept of atoms?

a)

Lavoisier

b)

John Dalton

c)

Democritus

d)

Maharishi Kanad

2.

What does Dalton's Atomic Theory state about atoms of different elements?

a)

They are indivisible.

b)

They can be created or destroyed.

c)

They have different masses and properties.

d)

They are identical in mass.

3.

What is the Law of Conservation of Mass?

a)

Mass can be destroyed in a reaction.

b)

Mass is always constant.

c)

Mass can be created in a reaction.

d)

Mass can neither be created nor destroyed.

4.

What is the smallest particle of an element called?

a)

Molecule

b)

Atom

c)

Compound

d)

Ion

5.

What is the relative atomic mass of Oxygen?

a)

16 u

b)

1 u

c)

23 u

d)

12 u

6.

What is a molecule?

a)

A single atom

b)

A compound

c)

Two or more atoms chemically bonded

d)

An element

7.

What is the atomicity of O₃?

a)

3

b)

4

c)

2

d)

1

8.

What does a chemical formula represent?

a)

The physical state of a substance

b)

The color of a substance

c)

The temperature of a reaction

d)

The symbolic representation of a compound

9.

What is the molecular mass of H₂O?

a)

22 u

b)

20 u

c)

18 u

d)

16 u

10.

What is Avogadro's number?

a)

6.022 × 10²²

b)

6.022 × 10²³

c)

6.022 × 10²⁴

d)

6.022 × 10²⁵

11.

How many moles are in 9 g of water?

a)

0.5 mol

b)

2 mol

c)

1.5 mol

d)

1 mol

12.

What is the mass of 1 mole of O₂?

a)

32 g

b)

36 g

c)

18 g

d)

16 g

13.

What is the atomicity of a monoatomic element?

a)

4

b)

3

c)

2

d)

1

14.

Which of the following is a diatomic molecule?

a)

S₈

b)

P₄

c)

H₂

d)

O₃