How many electrons are in this?
Is it 42?
- 1 decade agoFavorite Answer
Ca has atomic number 20 meaning it has 20 protons, and when it is neutral, 20 electrons. Since positive charge means more protons, that means a 2+ charge says the atom has 2 more protons than electrons. Since the number of protons didn't change, it had to lose 2 of those 20 electrons leaving it with 18 electrons.
- TaylorLv 41 decade ago
39K, 40K, and 41K have 20, 21, and 22 neutrons, respectively.