What organelle acts as a barrier of the cell? ​

cell membrane

Explanation:

it controls what comes and goes out of a cell

Cell membrane

Explanation:

It separates the interior of all cells from the outside environment (the extracellular space) which protects the cell from its environment.

samuel de champlain. in 1608, king henry iv sponsored pierre dugua, sieur de mons and samuel de champlain as founders of the city of quebec with 28 men. this was the second permanent french settlement in the colony of canada.

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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