Which of the following is true of a neutral halogen?
It has more valence electrons than the noble gas in its period
It has lower affinity for electrons than the alkali metal in its period
It has an unpaired electron in one of its orbitals
Its electron configuration ends with
An element from which of the following groups is most likely to react with a halogen?
Halogens
Alkali metals
Alkaline earth metals
Noble gases