Final answer:
The mass of 2.50 mol of calcium atoms is approximately 100 g.
Step-by-step explanation:
The molar mass of calcium (Ca) is 40.08 g/mol. The question asks for the mass of 2.50 mol of calcium atoms. To calculate this, we multiply the molar mass of calcium by the number of moles given.
Mass of calcium atoms = number of moles x molar mass
Mass of 2.50 mol of calcium atoms = 2.50 mol x 40.08 g/mol = 100.20 g
Therefore, the mass of 2.50 mol of calcium atoms is approximately 100 g (option D).