The number of neutrons in an atom of  is

(1) 23
(2) 11
(3) 34
(4) 12

The isotope used in the treatment of cancer of .......

(1) Iodine
(2) Cobalt
(3) Carbon
(4) Hydrogen

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

(1) Electron
(2) Atomic nucleus
(3) Proton
(4) Neutron

The number of protons, neutrons and electrons in four elements a, b, c and d are as follows :
(a) p = 6, n = 6, c = 6 
(b) p = 6, n = 7, c = 6 
(c) p = 18, n = 22, c = 18 
(d) p = 19, n = 21, c = 19 

In these : 
(1) Element a and b are isotopes and element c and d are isobars. 
(2) Element a and b are isotopes but element c and d are not isobars. 
(3) Element a and b are isobars and element c and d are isotopes. 
(4) Element a and b are isobars but element c and d are not isotopes.

The maximum number of electrons that can be accomodated in the 'L' shell of an atom is .....

(1) 2
(2) 4
(3) 8
(4) 16