What does electronegativity depend on?

• A. The number of protons
• B. The distance between electrons and the nucleus
• C. The atomic weight
• D. The number of protons and the distance between electrons and the nucleus

Answer: (D)

Electronegativity is how strongly an atom attracts electrons in a bond. This depends on the effective pull of the nucleus on the bonding electrons, which is determined by two main factors: the number of protons in the nucleus (more protons increase the positive charge pulling on electrons) and how far those bonding electrons are from the nucleus (larger distance weakens the pull). Inner electrons shield some of the nuclear charge, altering the effective pull. Taken together, the strength of attraction depends on both the number of protons and the distance between the electrons and the nucleus. The other choices miss one of these aspects: protons alone ignore distance and shielding; distance alone ignores the stronger pull possible with more protons; atomic weight does not dictate electronegativity.