| A | B |
|---|
| geologic time scale | outline of earths history |
| era | the longest division of geological time |
| big bang theory | suggests that all matter (anything that has weight and takes up space) and space were once concentrated in a great dense glowing mass. the mass exploded into billions of galaxies that are moving away from each other |
| theory | idea supported by evidence |
| law | ideas that can be tested and proven |
| pangea | all the continents on earth were once one giant land mass. Pangea is the name given to this land mass. It broke apart in the mesozoic era |
| fossils | a record of past life in the form of a track, a trace or remains preserved in rock |
| index fossils | fossils of an organism that lived in many places over a short time period; used to date the rock layer in which it is found |
| trilobite | an index fossil from the paleozoic era |
| ammonite | an index fossil from the mesozoic era |
| extinct species | species that has no living members |
| relative dating | the process of determining that one event happened before or after another event |
| geology | a science that deals with the history of the earth |
| radiometric dating | a technique that uses radioactivity to find the approximate age of certain rocks |
| half-life | the amount of ime needed for 1/2 of the radioactive atoms to break down |
