set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon?

a) 10

b) 6

c) 12

d) 14

Question : 2

The isotopes of an element have

a) same atomic number

b) same mass number

c) same number of neutrons

d) None of these

Question : 3

In atom, neutron was discovered by

a) Chadwick

b) Rutherford

c) J.J. Thomson

d) Newton

Question : 4

Adding electrons to an atom will result in a (an)

a) anion

b) cation

c) molecule

d) salt

Question : 5

Which of the following have equal number of neutrons and protons?

a) Deuterium

b) Fluorine

c) Hydrogen

d) Chlorine

Question : 6

The number of molecules in one mole of a gas is

a) 6.023 × 10²¹

b) 6.023 × 10²²

c) 6.023 × 10²³

d) 6.023 × 10²⁰