Question

Which among the given elements have similar chemical properties, as an atom of an element 'X' with an electronic configuration of 2, 8, 5?

• A. F (9)
• B. Na (11)
• C. N (7)
• D. Ar (18)

Answer 1

The correct option is C

N (7)

Elements having same valence electrons have similar chemical properties. The element 'X' has electronic configuration of 2, 8, 5. Thus, valence electron is 5.

F (Atomic number= 9): Electronic configuration = 2, 7
Na (Atomic number= 11): Electronic configuration = 2, 8, 1
N (Atomic number= 7): Electronic configuration = 2, 5
Ar (Atomic number= 18): Electronic configuration = 2, 8, 8

Nitrogen (N) have the same number of valence electron as the element 'X'. Hence, nitrogen will have similar chemical properties.