Question

Find the mass in grams.

a. 4.30 x 10^16 atoms He, 4.00 g/mol

b. 5.710 x 10^23 molecules CH4, 16.05 g/mol


c. 3.012 x 10^24 ions Ca^2+, 40.08 g/mol

Answer 1

a. divide the atoms by avogradros number to the moles, then multiply by 4g/mol

Answer 2

You must learn to do these yourself. They are worked the same way I showed you earlier in the evening except there are two factors. One to convert molecules or atoms to moles and the second to change from moles to grams.
#molecules x (1 mole/6.02 x 10^23 molecules) x (zz grams/mole) = ?? grams.

Answer 3

so a= 1.075*10^16