Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.

c)  A substance that cannot be broken down chemically into simpler substances.

Explanation:

The smallest particle that has the properties of an element, is the correct definition of an atom. A is the definition of matter; C is the definition of an element; and D is the definition of a molecule.

i'll try what topic lol

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs