Answer:
Centimeters of crystal ( in real life ) = 0.5 cm
Explanation:
Let us plan out our steps, and solve for each:
1. Given the information, let us create a proportionality as such:
24 = 1 ⇒ x - crystal size in real life
12 x
3. Now let us cross multiply, and solve through simple algebra:
12 = 24 * x,
x = 0.5 centimeters of the crystal in real life