Calculate the number of atoms in a 5.19×103 g sample of lithium.

Answer 1

This can be calculated by using the molar mass of lithium. The molar mass of lithium is 6.941 g/ mol.

If you take your starting mass, 5.19 * 10^3 g, and divide it by the molar mass, you get:

4.19*10^3 g / 6.941 g/mol = 747.731 mol

Then, recall that one mole of a substance is defined by 6.022*10^23 atoms of it (Avagadro's Number), you can multiply the number of moles by the number of atoms/mol:

747.731 mol * 6.022*10^23 atoms/mol = 4.503 * 10^26 atoms

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