Answer:
It approximately has 145 grams
Step-by-step explanation:
Calcium has an atomic mass of 40.08 g/mol. This means that one mole of Calcium atoms has a mass of 40.08 grams.
Since there are 6.022 x 10^23 atoms in one mole, 2.17 x 10^25 atoms of Calcium is equivalent to (2.17 x 10^25 atoms) / (6.022 x 10^23 atoms/mol) = 3.63 moles of Calcium.
Therefore, 2.17 x 10^25 atoms of Calcium has a mass of 3.63 moles * 40.08 g/mol = 145.44 grams.
Rounded to three significant figures, this is approximately 145 grams.