One mole of oxygen gas has a mass of g. one mole of oxygen gas has a mass of g. 32.0 6.022 × 1023 16.0 8 none of the above

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

catya your not at all which answer i've seen you do this on another question!