Basic Chemistry
matter - correct answer anything that occupies space and has mass
element - correct answer a pure substance that cannot be broken down into other
substances by chemical reactions
compound - correct answer substance containing two or more elements chemically
combined in a fixed ratio
atom - correct answer the smallest particle of an element that retains the properties
of the element
proton - correct answer subatomic particle having a positive charge; found in
nucleus
electron - correct answer subatomic particle having a negative charge; not in
nucleus but surrounds it
neutron - correct answer subatomic particle without a charge; found in nucleus
nucleus - correct answer protons and neutrons together; make up the center of an
atom
atomic number - correct answer identifies a specific element; equals the number of
protons in an atom of each element
radioactive isotope - correct answer an unstable atom in which the nucleus decays
(breaks down) releasing particles and energy
