Multiple choice

Given below is a column from Newlands’ table.

H
F
Cl
Co
Br

Which of the following elements is the odd one out?

  1. H

  2. F

  3. Co

  4. Br

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

H, F, Cl and Br have some similar properties as they all have valency 1 and exist in nature as diatomic molecules (i.e. in the form of H2, F2, Cl2, Br2). Cobalt is a transition metal and its properties are different from those of H, F, Cl and Br.