| A | B |
|---|
| geology | the study of the Earth |
| geologic time scale | a time line showing different evnts in geological history |
| era | distnctive historical period |
| The Big Bang Theory | suggests that all matter and space were once concentrated in a single great dense glowing mass. The mass exploded into billions of galaxies that are moving away from each other |
| theory | statement of possible truth |
| law | rules of natural phenomena |
| Pangeea | all the continents on Earth were once one giant land mass. It broke apart in the Paleozoic Era |
| fossils | hardened or petrified organisms |
| index fossils | fossils used to find the age of other organisms nearby |
| trilobite | index fossil alive durring the Paleozoic Era |
| ammonite | index fossil alive durring the Mesozoic Era |
| extinct | no longer in existance |
| relative dating | deciding the approximate time of something compared to when other things happened |
| radiometric dating | a technique that uses radioactivity to find the approximate age of certain rocks |
| half life | the amount of time needed for 1/2 of the radioactive atoms to break down |
