A potassium atom (atomic number 19) and a bromine atom (atomic number 35) can form a chemical bond through a transfer of one electron. The potassium ion that forms has 18 electrons.

What best describes the bromide ion that forms?

It is a negative ion that has one less valence electron than a neutral bromine atom.
It is a positive ion that has one less valence electron than a neutral bromine atom.
It is a negative ion that has one more valence electron than a neutral bromine atom.
It is a positive ion that has one more valence electron than a neutral bromine atom.