Find the number of atoms in a gold ring of mass 6.43 g.
The atomic mass of gold is 197 g/mole, so you have
6.43/197 = 0.03264 moles.
Each mole contains 6.02*10^23 atoms.
0.03264 * 6.02*10^23 = ____ atoms
To find the number of atoms in a gold ring, we need to use the concept of molar mass, Avogadro's number, and the given mass of the gold ring.
Here's the step-by-step explanation on how to calculate the number of atoms:
1. Determine the molar mass of gold (Au).
The atomic mass of gold (Au) is 197.0 g/mol. This means that 1 mole of gold has a mass of 197.0 grams.
2. Calculate the number of moles of gold in the given mass.
To do this, divide the given mass of the gold ring (6.43 g) by the molar mass of gold:
Number of Moles = Mass / Molar Mass
Number of Moles = 6.43 g / 197.0 g/mol
Using a calculator, this calculation gives:
Number of Moles ≈ 0.0327 mol
3. Apply Avogadro's number to convert moles to atoms.
Avogadro's number is 6.022 x 10^23 atoms/mol. This means that there are 6.022 x 10^23 atoms in 1 mole of any substance.
To find the number of atoms in the given mass, multiply the number of moles from step 2 by Avogadro's number:
Number of Atoms = Number of Moles x Avogadro's number
Number of Atoms ≈ 0.0327 mol x 6.022 x 10^23 atoms/mol
Using a calculator, this calculation gives:
Number of Atoms ≈ 1.97 x 10^22 atoms
Therefore, there are approximately 1.97 x 10^22 atoms in a gold ring with a mass of 6.43 g.