Question

Atomic numbers of elements are given below. Which of them would have the least electronegativity?

• A. $37$
• B. $19$
• C. $87$
• D. $105$

Answer 1

The correct option is C $87$

Electronegativity increases on moving along the period and decreases down the group in the periodic table. So alkali metals${}_{3}Li,{}_{11}Na,{}_{19}K,{}_{37}Rb,{}_{55}Cs,{}_{87}Fr$ have lowest electronegativity and out of these $Fr$ has lowest electronegativity.