Question

write the chemical symbols for three different atomic cations that all have 13 protons.

Explanation:

Step1: Identify the element

The element with 13 protons is aluminum, symbol - Al.

Step2: Form cations

Cations are formed by losing electrons. Aluminum can form cations with different charges by losing different numbers of electrons.
Aluminum can form $Al^{1 +}$, $Al^{2+}$, $Al^{3+}$.

Answer:

$Al^{1 +}$, $Al^{2+}$, $Al^{3+}$