Remember, the drug label will tell you: 1  what the drug is used for. 2  how to take the drug. 3  how to reduce the risk of drug interactions and unwanted side effects.
The units that divide the geologic time scale are Eons, Eras, Periods, and Epochs. Eons are the biggest, Eras are the second biggest and so on and so forth. So it goes Eons, E â¦ ras, Periods, and then Epochs. I know this because i just took a test on it in science so i know its right.
Geologic units are named and defined by the geologists who made the geologic map, based on their observations of the kinds of rocks and their investigations of the age of the rocks. As more information is gathered, perhaps by other geologists, new geologic units might be defined.