Which of the following elements would you expect to form an ion with a charge of negative three? Select all that apply. Select one or more:
a. Potassium
b. Phosphorus
c. Aluminum
d. Nitrogen

b.Phosphorus.

d.Nitrogen.

Explanation:

To know the charge of an ion, we need to consider the octet rule: an atom gains, loses or shares electrons to complete their valence shell with 8 electrons.

Which of the following elements would you expect to form an ion with a charge of negative three?

a.Potassium. NO. K has 1 electron in the valence shell so it loses 1 electron to form K⁺.

b.Phosphorus. YES. P has 5 electrons in the valence shell so it gains 3 electrons to form P³⁻.

c.Aluminum. NO. Al has 3 electrons in the valence shell so it loses 3 electrons to form Al³⁺.

d.Nitrogen. YES. N has 5 electrons in the valence shell so it gains 3 electrons to form N³⁻.