How Many Calcium and Fluorine Ions Are There in the Fluorite

Multiple Choice

How many calcium and fluorine ions are there in the fluorite unit cell shown below?

A) 4 Ca²⁺ and 2 ^-
B) 4 Ca²⁺ and 8 ^-
C) 2 Ca²⁺ and 4 ^-
D) 2 Ca²⁺ and 8 ^-
E) 4 Ca²⁺ and 4 ^-