Question

give the ion symbol for the ion that has 15 protons and 18 electrons.

Explanation:

Step1: Identify the element

The number of protons is equal to the atomic number. An atomic number of 15 corresponds to the element phosphorus (P).

Step2: Determine the charge

The number of electrons is 18, and the number of protons is 15. The charge of the ion is calculated as (number of protons) - (number of electrons) = \(15 - 18 = -3\).

Step3: Write the ion symbol

The ion symbol is written as the element symbol with the charge as a superscript. So, the ion is \( \text{P}^{3-} \).

Answer:

\( \text{P}^{3-} \)