| The Earth's atmosphere is mostly ____ and oxygen (O2) gasses. |
core |
| The Earth's ____ is mostly solid rock between its crust and core. |
full moon |
| A molecule of ____ contains three oxygen atoms. |
mantle |
| An underwater earthquake could generate a ____. |
nitrogen |
| The Earth's ____ is composed of hot iron and nickel. |
ozone |
| Clay, humus, sand, and ____ (quartz grains) are found in soil. |
seismology |
| The scientific study of earthquakes is called ____. |
silt |
| The Earth is between the Sun and the Moon during a ____. |
tsunami |
