To determine the number of atoms in a given mass of an element, you need to use Avogadro's number and the molar mass of the element.
Avogadro's number is approximately 6.022 × 10^23, and it represents the number of particles (atoms, molecules, or ions) in one mole of a substance.
The molar mass of magnesium (Mg) is approximately 24.31 grams per mole.
To calculate the number of atoms in 20 grams of Mg, you can follow these steps:
Determine the number of moles of Mg: Number of moles = Mass / Molar mass Number of moles = 20 g / 24.31 g/mol
Calculate the number of atoms using Avogadro's number: Number of atoms = Number of moles × Avogadro's number Number of atoms = (20 g / 24.31 g/mol) × (6.022 × 10^23 atoms/mol)
By performing the calculations, you would find the approximate number of atoms in 20 grams of Mg, which is about 4.94 × 10^23 atoms.