How many total atoms are there in 0.350 mol of potassium oxide (k2o)?

hints:
avogadro's number : 6.022 x 10^23
mass number of potassium : 39
mass number of oxygen: 16

You already have it in moles so that makes it easier to workout.  

Given:
There are 0.350 moles in this sample
There are 3 atoms in each potassium oxide molecule. 

How to solve:
1. Multiply the number of moles by Avogadro's number to convert moles into molecules. 
0.350 moles x  = 2.11 x 10²³ molecules.

2. There are 3 atoms per molecule so we need to multiply by 3. 

2.11 x 10²³ molecules x  = 6.33 x 10²³ atoms