Question

An atom has electronic configuration 2, 8, 7.
(a) What is the atomic number of this element?
(b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
N(7) F(9) P(15) Ar(18)

Answer 1

(a) The atomic number of this element is 17.
(b) It would be chemically similar to F(9) with configuration as 2, 7.