Answer:
698mg
Step-by-step explanation:
1 mole of any substance contains 6.02x10^23 atoms as explained by Avogadro's hypothesis. This means that 1mole of Ca also contains 6.02x10^23 atoms.
1mole of Ca = 40g
40g of CO2 contains 6.02x10^23 atoms.
Therefore, Xmol of Ca will contain 1.05 x 1022 atoms i.e
Xmol of Ca = (40 x 1.05 x 1022)/6.02x10^23 = 0.698g
Recall: 1g = 1000mg
0.698g = 0.698 x 1000 = 698mg