Question

The atomic number of an element tells us the number of ____________ and ____________.

a) Protons & neutrons

b) Protons & electrons

c) Neutrons & electrons

d) electrons & quarks

Answer 1

Ans:-

A,

Protons and neutrons

The atomic number of an element tells us the number of protons and neutrons.

The atomic number is closely related to the mass number , which is the no. Of protons and neutrons in the nucleus of an atom.

Rest of the given options are wrong because:-

- Atomic number is equal to the no. Of electrons so atomic number can not tell us about electrons and protons so, 2nd option is wrong.

- Atomic mass contains protons so 3rd and 4th are also wrong as here protons is not given.