Which of these are equal to 3.01 × 1023 particles

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

The answer is c. 320 g