Question

Predict and write the charges and symbols (e.g. Ca2) of the monatomic ions formed by the following atoms

Part 1 

Sulfur readily forms the following monatomic ion: 

Part 2 

Phosphorus readily forms the following monatomic ion: 

Part 3 

The monatomic ions above are both isoelectronic with 

Answer 1

1) Sulfur forms S2 2) Phosphorus forms p3- 3) Both are having 18 elections so, both are is electronic, with Argon having sumbe abol 'Ar'