Question

An atom of an element has 13 electrons. Its nucleus has 14 neutrons. Find out atomic no. and approximate atomic weight. Indicate the ' arrangement of electrons and the electro valency of the element.

Answer 1

No. of 'e'=13

No. of protons = 13 

No. of neutrons = 14

Atomic no. = No. of proton = 13 

App. at. wt. = No. of proton + No. of neutron 

= 13 + 14 = 27 

Electronic configuration : Is²,2s² 2p⁶,3s² 3p¹ 

Electro valency = + 3 i.e., no. of electrons in outermost shell.