2. Convert 5.3 x 1025 molecules of CO2 to moles.

moles CO2 = 88 mol

EXPLAIN:

In order to go from molecules of CO2 to moles of CO2, we have to use the following relationship:

I usually set up dimensional analysis questions like this:

Quantity sought = Quantity given x conversion factor

Now we just plug the values into the format I have above (make sure your units cancel out as you are going through this process, that's how you know if you are doing the calculations correctly or not):

moles CO2 = 5.3×10∧25 molecules×1mol/6.02×10∧23 molecules

moles CO2 = 88 mol

pop pop pop on a opp

the answer is b & c i believe : )