How many Cs atoms are there in a 53.7 gram sample of Cs?

Answer 1

This is a two-step calculation. First convert grams Cs to moles Cs. Then convert moles Cs to atoms Cs.

The atomic weight of cesium is 133 g/mol

1. To convert grams to moles:

moles Cs= 53.7 g Cs1 mol = 0.404 mol Cs133 g

Multiply by moles per gram. Grams cancel out.

2. To convert moles to atoms:

atoms Cs = 0.404 mol Cs6.02 x 1023 atoms = 2.43E+23 atoms Csmol

Multiply by atoms/mole. Moles cancel out.