| A | B |
|---|
| molecule | The smallest unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound. |
| mixture | Two or more substances that are not chemically united and that exist in no fixed proportion to each other. |
| proton | A positively charged part of an atom found in the nucleus |
| neutron | A neutral part of an atom, found in the nucleus of all atoms, except hydrogen. |
| electron | A negatively charged part oa an atom, found circling around the nucleus. |
| nucleus | A positively charged area within an atom, composed of neutrons and protons, and possessing almost all of the mass of the atom, but occupying only a small fractgion of the volume of the atom. |
| ion | An electrically charged atom formed by the loss or gain of one or more electrons |
| compound | A particle composed of two or more elements. |
| matter | Anything that has mass and takes up space. |
| isotope | One of two or more atoms having the same atomic number but different mass numbers. |
