What are canal rays?

If an atom contains one electron and one proton, will it carry any charge or not?

Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?

What do you think would be the observation if the α-particle scattering experiment is carried out using a foil of a metal other than gold?

Write the distribution of electrons in carbon and sodium atoms?

If K and L shells of an atom are full, then what would be the total number of electrons in the atom?

If number of electrons in an atom is 8 and number of protons is also 8, then (i) what is the atomic number of the atom and (ii) what is the charge on the atom?

What are the limitations of J.J.Thomson’s model of the atom?

What are the limitations of Rutherford’s model of the atom?

Describe Bohr’s model of the atom.

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes  and  in the sample?

If Z = 3, what would be the valency of the element? Also, name the element.

Composition of the nuclei of two atomic species X and Y are given as under

                 X              Y

Protons =   6              6

Neutrons = 6             8

Give the mass numbers of X and Y. What is the relation between the two species?

Put tick () against correct choice and cross () against wrong choice in the following question:

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

(a) Atomic nucleus

(b) Electron

(c) Proton

(d) Neutron

Put tick () against correct choice and cross () against wrong choice in the following question:

Isotopes of an element have

(a) the same physical properties

(b) different chemical properties

(c) different number of neutrons

(d) different atomic numbers

Put tick () against correct choice and cross () against wrong choice in the following question:

Number of valence electrons in Cl⁻ ion are:

(a) 16

(b) 8

(c) 17

(d) 18

Which one 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