When copper metal reacts with oxygen gas, black copper oxide, Cuo,
is formed. In an experiment it was
found that when copper reacted
completely with oxygen, 6.35g of
copper reacted with 1.60g of oxygen
gas, O,, to form 7.95g of copper oxide.
a Calculate the number of moles of
each reactant and product.
21

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

i think that the answer is c