Question

How many electrons are there in the L-shell of Boron?

(a) 3

(b) 2

(c) 1

(d) 4

The question was posed to me in an interview.

My question is taken from Electronic Configurations of Elements and the Periodic Table in chapter Classification of Elements and Periodicity in Properties of Chemistry – Class 11

Answer 1

The correct answer is (a) 3

Easy explanation: The atomic number of Boron is 5 and it contains two elements in the K-shell and three elements in the L-shell as well as 4 electrons in s-orbital and 1 electron and p-orbital. The element preceding Boron is beryllium and the element succeeding Boron is carbon.