Question

select the species which has relatively smallest size o,o-,o+
(o-oxygen)

Answer 1

O+<O<O-
O positive is the smallest as it has one less electron
O is the middle one
O negative is the largest as it has one more electron

Answer 2

$O^+$ has the relatively smallest size.

• O has eight electrons.
• In $O^-$ one extra electron is added. So, the nucleus can not attract the electrons strongly and the size of the species increases. It has a higher size than O.
• $O^+$ has seven electrons as one electron is removed from O. Thus the nucleus attracts the electrons strongly and the size of the species decreases. It has a lower size than O.
• The order of size is-
• $O^->O>O^+$