Question

An atom of an element contains 29 electrons and 35 neutrons. Deduce -

a. the number of protons 

b. the electronic configuration of that element.

Answer 1

a. In an atom, number of protons is equal to number of electrons. 

The given atom contains 29 electrons. 

∴ Number of protons = 29

b. The electronic configuration of an atom of an element containing 29 electrons is :

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰

[Note : Given element is copper (Cu) with Z = 29]