81.
Atomic number is the number equal to

82.
Rutherford’s scattering experiment proved the presence of

84.
The atomic number of carbon is 6 and its atomic mass is 12. How many are there protons in the nucleus of carbon ?

85.
An atom of an element has atomic number 17 and mass number 36. The number of neutrons in its nucleus is

86.
Atoms of same element having different mass numbers are called________

88.
The electronic configuration of an atom having atomic number ‘20’ is

89.
Nucleus of an atom consists of.

90.
Which of the following is not a nucleon?