Earth's History

Scientists know that Earth had an ocean by 4 billion years ago because

• fossil fish are found in rocks of that age.

• marine sedimentary rocks of that age can be dated.

• high tide lines are found around the basin of the ancient ocean.

• there was water and basins so there must have been oceans.

Early Earth was intensely hot because of

• short-lived radioactive decay.

• intense bombardment from asteroid impacts.

• contraction of materials due to gravity.

• all of these.

Tags

NGSS.HS-ESS1-6

Scientists know that Earth and Moon formed in the same part of the solar system because they have

• nearly the same ratio of rock to metal.

• experienced about the same number of asteroid impacts.

• the same oxygen isotope ratio.

• the same ratio of oxygen to other atmospheric gases.

Tags

NGSS.HS-ESS1-6

The densest part of planet Earth is the

• core.

• mantle.

• continental crust.

• oceanic crust.

_________________ is the separation of Earth into layers based on density

True or False-Earth accreted from the cloud of dust and gas known as the solar nebula nearly 1.6 billion years ago.

• True

• False

Tags

NGSS.HS-ESS1-6

True or False-Planets were created from gravity smashing together large masses of metals and rocks.

• True

• False

Volcanic _________________ was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases.

True or False-Due to Earth’s large size, it did not experience intense bombardment from asteroid impacts.

• True

• False

For a planet it’s size, Earth

• has a faster spin.

• is rounder.

• has a smaller core.

• has a high oxygen isotope ratio.