Question

How many moles of atoms are in 9.00 g of 13c?

Answer 1

The atomic weight of 13C should be pretty close to 13.0. (If you have the exact mass, use it in the problem.) So, 9.00 g / 13.0 g/mol = 0.692 moles Therefore, the answer should be 0.692 moles are in 9.00 g of 13C.

Answer 2

I'm pretty sure the answer is
9/13 moles