Question

What is the mass in grams of a magnesium sample which contains 4.130 * 10^23 magnesium atoms

Answer 1

Let's write Avogadro's number first:

1 mol Mg = 24.30 g = 6.022x10^23 atoms (it could be molecules, ions, etc.)

Procedure:

24.30 g Mg ------ 6.022x10^23 atoms Mg

x ------- 4.130x10^23 atoms Mg

x = 16.67 g Mg

Answer: 16.67 g Mg