Question

what will be the number of valence electrons in K plus​

Answer 1

Valence electrons are generally regarded as being 'the outermost electrons' for a given atom. Therefore, with neutral potassium, there is one valence electron. If we take away the outermost electron, we now have a new set of outermost electrons being the 8 electrons in the 3s and 3p orbitals.

Answer 2

atomic no. of pottassium =19

2,8,9 valence electron =9

K+= 2,8,8

valence electrons = 8