Question

The symbol P represents the element phosphorus. This element’s atomic number is 15. How many protons and electrons are in a P–3 ion?

Answer 1

  protons = 15
              electrons = 18

P gains 3 electrons to form P-3 ion to attain noble gas configuration 2,8,8

Answer 2

+15 + -15 = 0 charge

(+15) and 18 electrons (-18) which = -3 net charge on the P-3 ion.

Hope this helps!