3.01 * 10^ 23 partilces is equal to half a mole.
3.01 * 10^23 = 0.5 mole
Remember that 1 mole = 6.02 * 10^23 units.
That is Avogadro's number.
That number is a constant. You can say a mole of anything to refer to 6.02 * 10^23 units of that thing.
If you divide the number of particles by Avogadro's number you will obtain the number of moles of partilcles:
3.01 * 10 ^ 23 particles
--------------------------------------- = 0.5 mol
6.02 * 10 ^ 23 particle / mol