The Atmosphere

1. a gas that is needed for fire to burn and makes up 21% of dry air.
4. Water in the form of an invisible gas
6. a type of barometer that measures changes in air pressure without using a liquid
8. An invisible form of electromagnetic energy with wavelengths that are longer than red light; can be felt as heat
10. An envelope of gasses that surrounds the planet
13. A form of energy that can move through the vacuum of space
17. the outer layer of Earth that has no limit
19. A process where light is reflected in all directions
20. the last of the four main layers which can reach teamperatures of 1,800 Celcius
21. these, as well as steam, are not gas but are actually tiny liquid droplets of water in the troposphere
22. the layer of Earth that causes auroras
23. a layer of the atmosphere with increasing temperatures that contains the ozone layer
24. the trapping of heat near a planet’s surface by certain gasses in the planet’s atmosphere

2. the most abundant gas in the atmosphere
3. the first layer of earth closest to the crust;where weather happens
5. this greenhouse gas makes up around 0.04% of Earth's dry air
7. An invisible form of energy with wavelengths that are shorter than wavelengths for violet light
9. The direct transfer of energy by electromagnetic waves
11. A type of barometer consisting of a glass tube partially filled with mercury, with its open end resting in a dish of mercury.
12. A measurement of the amount of mass in a given volume; calculated by dividing the mass by the volume.
14. The distance above sea level; elevation
15. a layer of the atmosphere that protects Earth from meteors
16. The pressure caused by the weight of a column of air pushing down on an area
18. a type of gas that makes up less than 1% of the composition of dry air