Question #e461c

1 Answer
Oct 8, 2017

Argon

Explanation:

If you have an ionic charge of #+3#, then you have #3# more protons than electrons, so

#15 + 3 = 18# protons

so you have an element with #18# protons, therefore the atomic number is #18#.

Quickly checking a periodic table tells us this is Argon.