Question

What is the most stable monatomic ion formed from iodine?

Answer 1

Iodine belongs to the halogen group i.e. group 17 in the periodic table with an atomic number of 53.

The valence electron configuration for iodine is: 5s²5p⁶

When iodine accepts one electron it gains a complete octet configuration which imparts additional stability. This leads to the formation of I⁻ ion which is the most stable monatomic ion formed from iodine

I⁻ : 5s²5p⁷

Answer 2

Answer: The most stable monoatomic ion formed will be
`I^-`

Step-by-step explanation:

Monoatomic ion is defined as the ion which contains only one atom.

Iodine gas is the 53rd element of the periodic table having 53 electrons.

The electronic configuration of this element is:
`[Kr]5s^24d^(10)5p^5`

This element will easily gain 1 electron to attain stable electronic configuration and hence will carry a negative charge.

The ion formed when iodine atom gains 1 electron is iodine ion and is written as
`I^-`.The ion formed is an anion.

Hence, the most stable monoatomic ion formed will be
`I^-`