Answer:
The answer to your question is 478.2 g of Ca
Step-by-step explanation:
Data
mass of Ca = ?
atoms of Ca = 7.2 x 10²⁴
Process
To solve this problem you must remember that 1 mol of any substance equals Avogadro's number.
1.- Look for the atomic number of Calcium
Atomic number = 40 g
2.- Use proportions to calculate the atoms of Ca
40 g of Ca ------------------ 6.023 x10²³ atoms
x ------------------ 7.2 x 10²⁴ atoms
x = (40 x 7.2 x 10²⁴) / 6.023 x 10²³
x =2.88 x 10²⁶ / 6.023 x 10²³
x = 478.2 g