Ions: isoelectronic Noble Gas

Question

A monatomic ion with a charge of -2 has an electronic configuration of 1s²2s²2p⁶.

This ion is a(n) _______cationanion.

What is the chemical symbol of the noble gas this ion is isoelectronic with? .

What is the formula of the ion? 

Answer 1

As it has a negative charge, it is an anion.

The noble gas is Neon.

The formula is O^2-

Answer 2

This ion is an anion.

The chemical symbol of the noble gas this ion is isoelectronic with is Ne.

The formula of the ion is O^2-.