posted by melly on .
1 mole of an element or compound contains 6.20 times 10 to the 23rd power atoms or molecules of the element or compound. 1 mole of an element or compound has a mass equal to its mass number (or molecular weight) in grams. For example, 1 mol of hydrogen gas (H2) contain 6.02 times 10 to the 23rd power molecules and weights 2g. So what is the weight of 1 mole of pure sodium?