How many moles of sodium are present in a 65.06 g sample of sodium?

Here's what you would do:

65.06 g Na 1 mol Na

_________ * __________ = 2.830 mol Na

1 22.99 g Na

The 22.99 is the molecular mass of sodium, which can be found on the Periodic Table. If significant figures dont matter, you could change the decimal, maybe to 23.0 if you wanted. I just kept the problem with 4 significant figures.

Edit*: okay the equation got a little messed up, sorry. You do (65.06 grams over one) times (1 mol Na over 22.99 g Na)