To calculate the number of atoms in a given mass of a substance, you can use the following steps:
Determine the molar mass of the element. The molar mass of magnesium (Mg) is approximately 24.31 grams per mole.
Calculate the number of moles in the given mass by dividing the mass of magnesium by its molar mass: Number of moles = Mass (g) / Molar mass (g/mol)
In this case, for 6 grams of magnesium: Number of moles = 6 g / 24.31 g/mol
Use Avogadro's number (6.02 x 10^23 atoms/mol) to convert the number of moles to the number of atoms: Number of atoms = Number of moles x Avogadro's number
Substituting the values, we have: Number of atoms = (6 g / 24.31 g/mol) x (6.02 x 10^23 atoms/mol)
After performing the calculation, you will obtain the number of atoms in 6 grams of magnesium.