Question

How many moles are in 34.5 g of sodium?

Answer 1

$\text{Moles=}\frac{\text{mass of the element or molecule}}{\text{atomic mass or molecular mass}}=\text{ }\frac{34.5\text{ g}}{23\text{ g/mol (approx)}}=1.5\text{ moles}$

Atomic mass Na = 23 g /mol (from periodic table)