Heat is: A. Energy content of an object
B. The mass of the substance
C. The temperature of a substance
D. Energy transferred by a temperature difference

Answer is in the photo. I can't attach it here, but I uploaded it to a file hosting. link below! Good Luck!

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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!

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~ trueboss72