Which of the following statements is true? A)Physical properties cannot be tested without changing the chemical structure of the substance.
B)The compound potassium chloride (KCl) has different properties than potassium (K) and chlorine (Cl).
C)Increasing temperature will decrease the rate of a chemical reaction.
D)Under normal conditions, atoms have a positive charge.

Explanation:

B)The compound potassium chloride (KCl) has different properties than potassium (K) and chlorine (Cl).

b is the correct

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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