After Earth's formation 4.6 billion years ago, several processes kept the surface hot and molten (liquid)..Match the correct term to their description or picture.

| Draggable item | arrow_right_alt | Corresponding Item |
|---|---|---|
accretion | arrow_right_alt |
Extraterrestrial comets, asteroids, meteorites hitting Earth produced heat |
differentiation | arrow_right_alt |
Planet attracts matter, gets big and gravity compresses planet, producing heat |
radiation | arrow_right_alt |
Denser (heavier) elements settle into layers producing heat |
Bombardment from space material | arrow_right_alt | Earth's core produces heat from radioactive decay |
Re-order Earth's atmospheres from earliest (first) to present
Light, simple elements present get 'blown away' by solar winds
formation of water vapor and ammonia from volcanic outgassing as well as carbon dioxide
water vapor and oxygen present; sun has formed ozone and nitrogen
This type of organism produced much of Earth's early oxygen.

Match the description to the picture
Which of Earth's two types of crust is the densest (heaviest)?

How long ago did Earth form?

Which layer is solid iron
The sudden increase in diversity of animals is known as?
