Pushing down on the piston causes an increase in pressure and a decrease in the volume of the gas in the cylinder. this is best explained by the fact that

Pushing down on the piston causes an increase in pressure and a decrease in the volume of the gas in the cylinder. This is BEST explained by the fact that the pressure is always inversely proportional with volume at constant temperature and number of moles of substance.

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