Answer:
Step-by-step explanation:
To find the number of calcium atoms in a 30.5-g sample, we need to use the molar mass of calcium and Avogadro's number.
The molar mass of calcium (Ca) is approximately 40.08 g/mol.
First, let's find the number of moles of calcium in the 30.5-g sample:
moles = (mass of the sample) / (molar mass of Ca)
moles = 30.5 g / 40.08 g/mol ≈ 0.7607 moles
Now, we will use Avogadro's number (6.022 x 10^23 atoms/mol) to find the number of calcium atoms in the sample:
number of atoms = (number of moles) × (Avogadro's number)
number of atoms = 0.7607 moles × 6.022 x 10^23 atoms/mol ≈ 4.58 x 10^23 atoms
So, the 30.5-g sample of calcium contains approximately 4.58 x 10^23 calcium atoms.