Which example provides evidence of a chemical change? F Wood releases ash and smoke when burned.
G Rock particles separate when soil is being sifted
. H Boiling water bubbles when being heated.
J Sugar is not visible when dissolved in water.​

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