Question

How many atoms are in 3.690 moles of oxygen

Answer 1

1 mole of any substance contains Avogadro's number.  

So, 1 mole of O2= 6.023x10^23 molecules  

3 mole of O2= 6.023x10^23x3 molecules  

= 1.8069x10^24 molecules  

Each molecule of Oxygen has 2 atoms.  

therefore,  

1.8069x10^24 molecules= 1.8069x10^24 x 2 atoms  

= 3.6138x10^24 atoms.