The Living World 8th Edition by George Johnson

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The smallest particle into which a substance can be divided and still retain all of its chemical properties is
A) matter.
B) an atom.
C) a molecule.
D) mass.
The property that distinguishes an atom of one element (carbon, for example) from an atom of another element (oxygen, for example) is
A) the number of electrons.
B) the number of protons.
C) the number of neutrons.
D) the combined number of protons and neutrons.