| A | B |
|---|
| Atom | the smallest particle of an element that still retains the properties of the element |
| Elements | substance with atoms that are all alike |
| Chemical reaction | process in which one or more substances are changed into new substances |
| Law of conservation of mass | states that the mass of all substances present before a chemical change equals the mass of all the substances remaining after the change |
| Alpha particles | particles consisting of two protons and two neutrons that is emitted from a decaying atomic nucleus |
| Atomic number | number of protons in an atom’s nucleus |
| Electron cloud | area around the nucleus of an atom where the atom’s electrons are most likely to be found |
| Isotopes | atoms of the same element that have different numbers of neutrons |
| Plasma | matter consisting of positively and negatively charged particles. A plasma is an ionized gas. This means the atoms and molecules that make up a plasma are charged. A plasma is characterized by its temperature, density and electrical conductivity. Its particles are very far apart and so are very compressible |
| Sublimation | the process of a solid changing directly to a vapor without forming a liquid |
| Density | mass per unit volume of a material |
| Physical property | is any characteristic of a material that you can observe without changing the identity of the substances that make up the material |
| Melting point | the temperature at which a solid begins to liquefy |
| Boiling point | is the temperature at which the pressure of the vapor in the liquid is equal to the external pressure acting on the surface of the liquid |
| Atomic mass | is the sum of the number of protons and the number of neutrons in the nucleus of an atom , the mass of an atom |
| Probability space | is the space that an electron is most likely to appear in at a given energy level |
| Orbital | the space defined by the orbit of the electrons |
| Valence shell | the highest energy level orbital containing electrons |
| Valence electrons | are the outer electrons in the valence shell. They have the weakest electromagnetic force pulling them towards the nuceus |
| Intrinsic – | properties of a substance that do not depend on the amount of matter present in the sample |
| Extrinsic | properties that depend on the amount of matter present |
| Phases | the different states that matter exists in (the 4 states are solid, gas, liquid, plasma) |
| Solid | the atoms or molecules that comprise a solid are packed closely together, in fixed positions relative to each other. Solids are resistant to changes in volume which means they are incompressible. A solid does not conform to the container it is placed in. Solids are incompressible |
| Liquid | the molecules that make up a liquid can move relative to one another but are fixed within the volume of the liquid by temperature and pressure. A liquid conforms to the container it is in but may not fill that container . Liquids are generally incompressible. |
| Gas | the atoms and molecules that make up a gas move independently of one another . Because the particles of a gas are far apart, gases are compressible. The amount of space between them is determined by the temperature and pressure of the gas, as well as the volume of the container in which it is placed. A gas placed in a container will spread out to uniformly fill that container. |
| Freezing point | of a substance is the temperature at which a liquid becomes solid or freezes. |
| Condensation point | is the temperature at which gas becomes a liquid. |
| Deposition – | is the condensation of a substance directly from a vapor to a solid without going through the liquid phase. |
