| A | B |
|---|
| sphere | a ball or globe |
| hydrosphere | the water part of the earth |
| lithosphere | the solid, rocky part of the earth |
| continents | large land areas |
| atmosphere | the air around the earth |
| bacteria | tiny organisms found in soil, water, and air |
| troposphere | the lowest layer of the atmosphere, where weather occurs |
| tropopause | the top of the troposphere, where the troposphere ends |
| stratosphere | the second layer of the atmosphere, where the temperature does not change much and where there is much ozone |
| ionosphere | an upper layer of the atmosphere that has ions and reflects radio waves |
| ozone | a form of oxygen that stops ultraviolet light rays |
| ion | a charged particle |
| radiant energy | giving off radiant energy |
| absorb | take in |
| transmit | allow to pass through |
| conduction | a method of moving heat by contact |
| convection current | the upward movement of warm air and downward movement of cool air |
| hemisphere | half of a sphere |
| mercury barometer | an instrument that uses a column of mercury to measure air pressure |
| aneroid barometer | an instrument that measures air pressure but uses no liquid |
| water vapor | molecules of water in the air |
| air currents | up-and-down movements of air |
| horizontal movement | moving across the surface of the earth |
| winds | horizontal movements of air |
| rotate | spin like a top |
| breeze | a light wind |
| monsoon | wind that changes direction with the seasons |
| weather vane | instrument used to measure wind direction |
| anemometer | instrument used to measure wind speed |
| evaporation | changing from a liquid to a gas |
| transpiration | the process by which plants five off water vapor to the atmosphere |
