| A | B |
|---|
| matter | anything that has volume and mass |
| element | natural or artificial substance that cannot be broken down into simpler substances |
| nucleus | positively charged center of an atom |
| proton | atomic particle that has mass and a positive charge |
| neutron | atomic particle that is neutral and has about the same mass as a proton |
| electron | tiny atomic particle with little mass and a negative electric charge |
| atomic number | number of protons in the nucleus |
| mass number | number of protons and neutrons in the nucleus |
| isotope | an atom of an element with a different mass number than the element but the same properties |
| ion | an atom that gains or loses an electron |
| compound | atoms of two or more elements that are chemically combined |
| chemical bond | force that holds the atoms of elements together in a compound |
| covalent bond | attraction of two atoms for a shared pair of electrons that holds atoms together |
| molecule | combination of atoms joined by covalent bonds |
| ionic bond | attractive force between two ions with opposite charge |
| metallic bond | positive ions of metal held together by the negative electrons between them |
| chemical reaction | change of one substanced into another substance |
| solution | homogeneous mixture whose components cannot be distinguished |
| acid | solution containing a substance that produces hydrogen ions (H+) |
| base | substance that produces hydroxide ions (OH-) |
| crystalline structure | regular geometric pattern of particles in most solids |
| glass | solid that consists of densely packed atoms with a random arrangement and lacks crystals |
| evaporation | change of state from a liquid to a gas |
| plasma | hot, highly ionized, electrically conducting gas |
| condensation | process by which a cooling gas changes into a liquid |
| sublimation | process by which a solid slowly changes to a gas without first entering a liquid state |
