Question

11.the masses number of electron is 18.it contains 7 electron. What is the number of protons and neutrons in it?

Answer 1

As the atomic number = number of protons

Atomic mass = number of protons + number of neutrons

and number of electron = number of protons for a neutral atom.

Therefore atomic number = 7 and atomic mass of the above element is 18,

Which means the number of protons = 7

Number of neutrons = 18-7

= 11