In the NaCl crystal structure:
The total number of Na+ and Cl− ions per unit cell is:
\[ 4 \, \text{Na}^+ + 4 \, \text{Cl}^- = 8 \, \text{ions} \]
Therefore, the total number of Na+ and Cl− ions per unit cell of the NaCl crystal is:
\[ \boxed{8 \, \text{ions}} \]



