Number of valence electrons in Cl- ion are:

(a) 16

(b) 8

(c) 17

(d) 18

Rutherford's alpha-particle scattering experiment was responsible for the discovery of:

(a) Atomic nucleus (b) Electron

(c) Proton (d) Neutron

Isotopes of an element have :

(a) the same physical properties

(c) different number of neutrons

(b) different chemical properties

(d) different atomic numbers

Which of the following is a correct electronic configuration of sodium?

(a) 2, 8 (b) 8, 2, 1

(c) 2, 1, 8 (d) 2, 8,1

Complete the following table: