Question

Explain the trends in the following properties, with reference to group-16?

Electronegativity.

Answer 1

Electronegativity.
On moving down the group the electrongegativity of group-16 elements decreases from oxygen to polonium. This is because of the fact that on moving down in a group the size of an atom increases which results a decrease in effective nuclear charge.
Therefore, electronegativity decreases.
Oxygen is the second most electronegative element after fluorine. $(O=3.5,F=4)$

Elements	O	S	Se	Te	Po
Electronegativity	3.5	2.5	2.4	2.1	2.0

On moving across a period i.e., from group 15 to 16 in a periodic table, electronegativity increases. This is because on moving from left to right the effective nuclear charge increases which results in increase in the nuclear pull on outer electrons resulting in higher electronegativity.