Question

There are 17 protons in an atom. The mass number of the atom is 35.
(i) Write down it's electronic configuration. (1)
(ii) How many neutrons are present in it?

Answer 1

Explanation:

An atom is neutral. So it will have as many electrons as it has protons. So it will have 17 electrons.

i) 2, 8, 7

No. of neutrons = Mass number - Proton number

ii) 18

Hope it helps.