The charge on an ion is A always positive. B zero. C always negative. D either positive or negative. 2. According to the octet rule, a calcium atom has a tendency to A lose one electron. B gain two electrons. C lose two electrons. D gain one electron.

D either positive or negative.

Explanation:

an atom is converted into ion only when the the atom lose or gain an electron

If an isolated atom will gain excess electrons then in that case the atom will become a negative ion

While if the atom will lose the electron then it will convert into a positive ion.

so ion may be positive or negative both kind

It may either lose or gain electrons one or more than one

so here correct answer would be

D either positive or negative.