Question

A sample of carbon-12 has a mass of 6.00 g. How many atoms of carbon-12 are in the sample?

I have the answer but I don't understand how to solve it.

Answer 1

Carbon - 12 : m = 6.00 g
From the Periodic system: Molar mass of C - 12 : M = 12 g / mol
n = m / M = 6 g / 12 g/mol = 0.5 mol ( the number of moles )
N a = 6.02 * 10 ^23 mol^(-1) ( Avogadro`s constant )
N = n * N a = 0.5 mol * 6.02 * 10 ^23 = 3.01 * 10^23
Answer:
3.01 * 10^23 atoms of Carbon -12 are in the sample.