Question

An element with the electron configuration [noble gas]ns2(n - 1)d10np3 has ____________ valence electrons.

Answer 1

Step-by-step explanation:

Electronic configuration = ns²( n-1 ) d¹⁰np³

Valance electron is the electron in the outermost shell . Here outermost shell is n and total number of electron in it is 2 + 3 = 5 ( 2 electron in s and 2 in p subshell ) . Therefore no of valance electron is 5 .