Question

question 4 of 10
why do nonmetals tend to gain electrons to form negative ions?

a. they have fewer protons in their nuclei, so they attract electrons.

b. they gain electrons to balance the protons in their nuclei.

c. they have low electronegativities.

d. they gain the few electrons they need to form full octets.

Explanation:

• Option A: Nonmetals generally have more protons (higher atomic number in their group) and higher electronegativity, so fewer protons is incorrect.
• Option B: Gaining electrons to balance protons is not the main reason; the goal is octet stability, not just charge balance.
• Option C: Nonmetals have high electronegativities (tend to attract electrons), so "low electronegativities" is wrong.
• Option D: Nonmetals are close to having a full octet (8 valence electrons, or 2 for H/He). Gaining a few electrons (e.g., Cl gains 1, O gains 2) allows them to achieve a stable noble - gas electron configuration (full octet), which is the driving force for forming negative ions.

Answer:

D. They gain the few electrons they need to form full octets.