| A | B |
|---|
| smog | a fog that has become polluted with smoke |
| gravity | attraction between all matter; force that pulls on all objects that have mass |
| mixture | combinations of two or more substances that have NOT combined to form new, pure substances |
| longitude | distance east or west of the prime meridian |
| latitude | distances north or south of the equator |
| hemisphere | either of the 2 halves into which a sphere is divided by a plane that passes through its center |
| radiation | energy that ttravels by waves in all directions from its source |
| chlorofluorocarbons | group of chemical compounds used in refrigerators, aerosol sprays, and foam packaging |
| Equator | imaginery line at 0 degrees latitude (half way between North & South poles) |
| jet stream | narrow belt of strong winds that blows near top of troposphere |
| Element | Naturally occuring or synthetic material that cannot be broken down; has a unique set of properties |
| Ozone | Poisonous, blue, unstable gaseous form of oxygen that has three atoms per molecule rather than the usual two |
| compound | Pure substance produced when elements combine, and whose properties are different from those of the elements from which it is formed |
| pressure | The amount of force applied per unit of area of a surface |
| atmosphere | the gas that surrounds a body in space and is held by the body's gravitational field |
| condensation | the process by which part or all of a gas or a mixture of gases becomes a liquid |
| hydrosphere | the waters of the Earth as distinguished from the atmosphere and the solid matter |
| evaporation | to change into the form of a vapor or gas |
| convection | Transfer of thermal energy when particles move from one place to another where there is a temperature difference |
