Determine the number of atoms in 51.0 grams of sodium, Na. (The mass of one mole of sodium is 22.99 g.)

The answer is

To find the number of atoms of sodium we use the formula

N = n × L

where

n is the number of moles

N is the number of entities

L is Avogadro's constant which is

We need to find the number of moles first

The formula is

where

M is the molar mass

m is the mass

n is the number of moles

From the question

M = 22.9 g/mol

m = 51.0 g

n = 2.227 moles

So the number of sodium atoms is

We have the final answer as

Hope this helps you