Samacheer Kalvi 10th Science Guide Atoms and Molecules Questions - 1

Question: 1

Which of the following is a triatomic molecule?

(A) Carbon dioxide

(B) Hydrogen

(C) Helium

(D) Glucose

Ans: A

Carbon dioxide

Question: 2

1 mole of any substance contains _____ molecules.

(A) 3.0115 × 1023

(B) 6.023 × 1023

(C) 6.023 × 10-23

(D) 12.046 × 1023

Ans: B

6.023 × 1023

Question: 3

In the nucleus of 20Ca40, there are

(A) 20 protons and 20 neutrons

(B) 20 protons and 40 neutrons

(C) 20 protons and 40 electrons

(D) 40 protons and 20 electrons

Ans: A

20 protons and 20 neutrons

Question: 4

Which of the following has the smallest mass?

(A) 1 atom of He

(B) 2g of He

(C) 1 mole atoms of He

(D) 6.023 × 1023 atoms of He

Ans: A

1 atom of He

Question: 5

The gram molecular mass of oxygen molecule is

(A) 16 g

(B) 17 g

(C) 18 g

(D) 32 g

Ans: D

32 g

Question: 6

The volume occupied by 1 mole of a diatomic gas at S.T.P. is

(A) 5.6 litre

(B) 11.2 litre

(C) 22.4 litre

(D) 44.8 litre

Ans: C

22.4 litre

Question: 7

Which of the following statement is incorrect?

(A) One mole of electrons stands for 6.023 x 1023 electrons

(B) One mole of hydrogen gas contains Avogadro’s number of atoms

(C) 12 gram of C-12 contains Avogadro’s number of atoms

(D) One mole of oxygen gas contains Avogadro’s number of molecules

Ans: D

One mole of hydrogen gas contains Avogadro’s number of atoms

Question: 8

Which of the following represents 1 amu?

(A) Mass of O – 16 atom

(B) Mass of a hydrogen atom

(C) Mass of a C – 12 atom

(D) $${1}/{12}$$thof the mass of C – 12 atom

Ans: D

$${1}/{12}$$th of the mass of C – 12 atom

Question: 9

Mass of 1 mole of Nitrogen atom is

(A) 14 g

(B) 28 g

(C) 14 amu

(D) 28 amu

Ans: A

14 g

Question: 10

The volume occupied by 4.4 g of CO2 at S.T.P

(A) 0.1 litre

(B) 0.24 litre

(C) 2.24 litre

(D) 22.4 litre

Ans: C

2.24 litre