Question

how many electrons does phosphorous (p) need to gain to have a stable outer electron level?
1
2
3
4

Explanation:

Step1: Determine P's valence electrons

Phosphorus has 5 valence electrons.

Step2: Recall stable - electron - level rule

A stable outer electron level usually has 8 electrons (octet rule).

Step3: Calculate electrons to gain

8 - 5=3.

Answer:

C. 3