Physical Science

2. energy that is transferred as a consequence of temperature differences
3. a dense, icy pack of old snow
7. a gradual change
11. the sum of all water on a planet
14. the mass of air surrounding a planet
15. the phenomenon that occurs when individual molecules are so strongly attracted to each other that they tend to stay together, even when exposed to tension
16. a measure of the energy of random motion in a substance's molecules
17. the quantity of a substance within a certain volume
19. a measure of the mass of dissolved salt in a given mass of water
20. a steady condition that prevails day in and day out in a particular region of the earth
22. a substance that contains different compounds and/or elements
23. the region of the atmosphere above an altitude of roughly 460 km
24. a chemical process by which oxygen reacts with a fuel to release energy
25. an atom that has lost or gained electrons so it has a net electrical charge
26. a community of organisms, along with their environment, functioning as a unit
27. an instrument used to measure atmospheric pressure

1. magma that flows out of a volcano
2. the moisture content of air
4. a substance composed of only one type of molecule
5. a poisonous gas composed of three oxygen atoms bonded together
6. the process by which a gas turns into a liquid
8. evaporation and condensation of a mixture to separate out the mixture's individual components
9. the smallest chemical unit of matter
10. a substance that does not conduct electricity very well
12. the use of electricity to break a molecule down into smaller units
13. evaporation of water from plants
18. a collection of atoms that all have the same number of protons
21. the lower layer of earth's atmosphere, which exists from ground level to roughly 80km above sea level