How many atoms are in 151 grams of calcium?

To determine the number of atoms in 151 grams of calcium, first calculate the number of moles of calcium using its molar mass, which is approximately 40.08 grams per mole. Dividing 151 grams by 40.08 grams/mole gives about 3.76 moles of calcium. Since one mole contains Avogadro's number of atoms (approximately (6.022 \times 10^{23})), multiplying 3.76 moles by (6.022 \times 10^{23}) atoms/mole gives roughly (2.26 \times 10^{24}) atoms of calcium.