Question

Which one of the following elements forms a negative ion?Group of answer choicesNa0MgHeAl

Answer 1

Oxygen (O) forms a negative ion. (second option)

Step-by-step explanation:

The ion form of each element is:

`\begin{gathered} Na^(1+) \\ O^(2-) \\ Mg^(2+) \\ He^0 \\ Al^(3+) \end{gathered}`