What is the mass of a sample of copper that contains 4.78 x 1023 atoms?

50.45679

Explanation:

mass of 1 mole(6.02 x 10^23atoms) of copper: 63.546g

so,

63.546g x 4.78 x 10^23 / 6.02 x 10^23 = 50.45679g (you could round this to the nearest decimal if u wish so)

elements make up everything, and they combine to make compounds.

the answer is c

answer carbon and three oxygen atoms;