NCERT Class 9 MCQ Quiz Hub

1. Which of the following correctly represents the electronic distribution in the Mg atom?
3, 8, 1
2, 8, 2
1, 8, 3
8, 2, 2

2. Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in the discovery of
electron
proton
nucleus in the atom
atomic mass

3. Which of the following are true for an element? (i) Atomic number = number of protons + number of electrons (ii) Mass number = number of protons + number of neutrons (iii) Atomic mass = number of protons = number of neutrons (iv) Atomic number = number of protons = number of electrons
(i) and (ii)
(i) and (iii)
(ii) and (iii)
(ii) and (iv)

4. Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order (i) Rutherford’s atomic model (ii) Thomson’s atomic model (ii) Bohr’s atomic model
(i), (ii) and (iii)
(ii), (iii) and (i)
(ii), (i) and (iii)
(iii), (ii) and (i)

5. The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
13
10
14
16

6. The first model of an atom was given by
N. Bohr
E. Goldstein
Rutherford
J.J. Thomson

7. An atom with 3 protons and 4 neutrons will have a valency of
3
7
1
4

8. Which of the following statement is always correct?
An atom has equal number of electrons and protons.
An atom has equal number of electrons and neutrons.
An atom has equal number of protons and neutrons.
An atom has equal number of electrons, protons and neutrons.

9. Which of the following statements about Rutherford’s model of atom are correct? (i) Considered the nucleus as positively charged. (ii) Established that the a-particles are four times as heavy as a hydrogen atom. (iii) Can be compared to solar system. (iv) Was in agreement with Thomson’s model.
(i) and (iii)
(ii) and (iii)
(i) and (iv)
only (i)

10. How many electrons are present in M-shell of an element with atomic number 20?
5
8
12
18

11. An alpha particle is also known as:
subatomic particle
an unionised helium atom
a neutral particle
a doubly-charged helium ion

12. The charge on an electron is equal to:
1.6 × 10-19 C of -ve charge
2.6 × 10-19 C of -ve charge
1.6 × 10-22 C of -ve charge
1.6 × 10-23 C of -ve charge

13. Which of the following isotope is used in the treatment of blood cancer?
P-32
I-131
Co-60
any of these

14. Isobars do not differ in the number of
protons
electrons
neutrons
nucleons