Question

How many protons does this atom have if it has a -3 charge and 18 electrons?

Answer 1

Answer: The atomic number is 21, which means that scandium has 21 protons. While a neutral atom for scandium would have the same number of electrons as protons, the ion is shown to have a +3 charge. This means it has 3 fewer electrons than the neutral atom or 21 - 3 = 18 electrons.

Step-by-step explanation:

Answer 2

21 protons

Step-by-step explanation:

The atomic number is 21, which means that scandium has 21 protons. While a neutral atom for scandium would have the same number of electrons as protons, the ion is shown to have a +3 charge. This means it has 3 fewer electrons than the neutral atom or 21 - 3 = 18 electrons.