| Definition | Term |
|---|
| 2.5 billion years ago to 543 million years ago | |
| outermost layer of Earth | |
| Fourth and last layer absorbs highly energetic solar radiation | |
| Wind is deflected by Earth spinning on its axis | |
| 543 million years ago to today | |
| tiny particles and droplets of liquids | |
| radius - 3,480 km, liquid iron, reason for the magnetic field | |
| Movement of air due to changes in air pressure | |
| 3.8 billion years ago to 2.5 billion years ago | |
| | Definition | Term |
|---|
| Where tectonic plates slide past each other | |
| layer that makes up nearly 70% of Earth’s interior, composed of oxygen, silicon, and magnesium | |
| Located 15 miles above the surface, is very thin | |
| 4.6 billion years ago to 3.8 billion years ago | |
| Outermost layer where the atmosphere begins to blend into space | |
| 31 to 50 miles above the surface, is the coldest layer | |
| Where two plates move toward each other | |
| Where two plates move apart | |
| Layer that is closest to the Earth’s surface | |
|
Periodic Table 
The Nine Planets 
Digits of Pi
