Study Guide
Quick meanings for every word. Pair Tier 3 words with pictures to support newcomers.
Beginner ELL Core Idea
- Air surrounds Earth and changes.
- Air pushes and moves.
- Heat makes air rise. Cool air falls.
- Weather happens in the troposphere.
| Word | Meaning |
|---|---|
| Air Pressure | The force created by the weight of the air above you, pushing outward in every direction. |
| Atmosphere | The layer of gases that surrounds Earth and is held in place by gravity. |
| Gas | A state of matter with no fixed shape or volume — its particles spread out to fill any container. Air is a mix of several of these. |
| Gravity | A force that pulls objects toward each other. On Earth, it pulls everything toward the ground. |
| Pressure | The amount of force pushing on a given area. The same force squeezed into a smaller area means more of this. |
| Temperature | A measure of how hot or cold something is. |
| Weather | The day-to-day conditions in the sky — like rain, sun, wind, or snow — at a specific place and time. |
| Altitude | How high something is above sea level. |
| Barometer | A tool used to measure the force of the air pushing down from above. |
| Biosphere | The parts of Earth — from deep oceans to mountain tops — where living things exist. |
| Chemical Composition | What something is made of, in terms of the elements and compounds it contains. |
| Density | A measure of how much mass is packed into a given amount of space. More mass in the same space means a higher value. |
| Exosphere | The outermost layer of Earth's gases, where the air thins out and gradually blends into space. |
| Greenhouse Effect | The warming that happens when certain gases in the air trap heat near Earth's surface instead of letting it escape into space. |
| Hydrosphere | All of Earth's water — oceans, lakes, rivers, ice, and groundwater — combined. |
| Ionosphere | A region high in the sky where sunlight knocks electrons loose from gas particles, leaving behind a layer of charged particles. It overlaps the mesosphere and thermosphere. |
| Lithosphere | Earth's solid outer shell — the crust and the rigid upper part of the mantle beneath it. |
| Mesopause | The boundary at the top of the coldest air layer, where temperature stops dropping and starts rising again with height. |
| Mesosphere | A layer of gases high above Earth with the coldest temperatures in the whole atmosphere. Most meteors burn up here. |
| Ozone | A gas made of three oxygen atoms bonded together, which absorbs most of the Sun's harmful ultraviolet rays. |
| Stratopause | The boundary at the top of the layer where jet planes often fly, where temperature stops rising and starts dropping with height. |
| Stratosphere | A calm layer above the lowest layer of air, where temperature rises with height and most of Earth's ozone is found. |
| Troposphere | The lowest layer of gases surrounding Earth, where nearly all clouds, storms, and everyday weather happen. |
| Thermosphere | A layer high above Earth where the few remaining gas particles absorb intense solar energy and reach very high temperatures — even though the air there is far too thin to feel warm. |
| Tropopause | The boundary at the top of the lowest air layer, where rising air stops cooling and temperature levels off with height. |
| Variations | Changes or differences between one thing and another. |
| Water Vapor | Water in its gas form, invisible and mixed into the air. |