Evidence of a chemical change includes a) change in size. b) change in color. c) change in shape. d) change in weight. evidence of a chemical change includes a) change in size. b) change in color. c) change in shape. d) change in weight.

The answer is actually B) change in color

Explanation:

Here's why: A chemical change changes the substance. Evidence of a chemical change include evolving gas and changes in color or temperature

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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d

explanation: