The tendency of a nonmetal atom to accept electrons and form an anion, which increases across a period, is called its:

1. Across a period the effective nuclear charge increases. 2. Valence electrons are held tightly and extra electrons are attracted strongly. 3. The tendency to form an anion by gaining electrons is electronegativity. 4. This is the nonmetallic character of the element. 5. Rule out A: electropositivity is the electron-losing (metallic) tendency. _Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 2 "Periodic Classification of Elements", p.36_