There are only two isotopes in made-up element "Z". The first isotope has a mass of 79 amu and the second isotope has a mass of 86 amu. If each isotope comprises half of the total elemental abundance, what is the atomic mass of the element?

lol for the pointsss

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.

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~ trueboss72

the answer is c

tell me if wrong