Question

The period with electron in the shells k,L and M

Answer 1

3rd period since the period is determined by the no of shells

Answer 2

Explanation:

A period in which all the elements have electrons present in K, L and M shell is third period.

For example, sodium is a third period element. Atomic number of sodium is 11 and its electronic distribution is 2, 8, 1.

That is, in K shell there are 2 electrons, in L shell there are 8 electrons and in M shell there is 1 electron.