Crossword puzzle clue "charge carrier that forms a bond within each of this puzzle's four longest answers"

an electrically-charged particle formed by loss or gain of electrons by an atom

a seed-bearing plant whose aerial parts do not persist above ground at the end of the growing season

a person obsessed with computers at the expense of human interaction, also NURD

a small industrious insect

ASP, a venomous snake, also ASPICK

a head or point of land jutting into the sea or a lake

ESSE, (Latin) actual existence, essence