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Substances&Mixtures
Term | Definition |
---|---|
MaKenna | Leddy |
matter | anything that has mass and takes up space. |
atom | a small article that is the building block of matter. |
substance | matter with a composition that is always the same. |
element | substance made of only one kind of atom. |
molecule | 2 or more atoms that are held together by chemical bonds and act as a unit. |
compound | substance made of 2 or more elements that are chemically joined in a specific combination. |
mixture | matter that can vary in composition. |
heterogeneous mixture | a mixture in which the substances are not evenly mixed. |
homogeneous mixture | mixture in which 2 or more substances are evenly mixed, but not bonded together. |
nucleus | region at the center of an atom that contains most of the mass of an atom. |
proton | positively charged particle in the nucleus of an atom. |
neutron | uncharged particle in the nucleus of an atom. |
electron | negatively charged particle that occupies the space in an atom outside the nucleus. |
electron cloud | region surrounding an atom's nucleus where 1 or more electrons are most likely to be found. |
isotope | 1 of 2 or more atoms of an element having the same number of protons but a different number of neutrons. |
ion | an atom that has a charge because it has gained or lost electrons. |
atomic number | number of protons in the nucleus of an atom of an element. |