What is the best category for nf3? 1. amphoteric ion 2. lewis acid 3. salt 4. bronsted-lowry acid 5. arrhenius acid 6. arrhenius base 7. lewis base 8. weak electrolyte?

Answer is: 7. Lewis base.

Nitrogen trifluoride (NF₃) a Lewis base, because it can donate its lone pair of electrons (lone pair of electrons are in nitrogen atom).

Lewis base is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid.

Nitrogen-fluorine compound is a colorless, odorless and nonflammable gas.