Question

The _______ era encompasses 90% of Earth's history. Some of the oldest rocks ever discovered on Earth were found in western Greenland and were dated at approximately _______ billion years using isotopic dating methods. The break-up of the most recent supercontinent of _______ is responsible for the current arrangement of continents. During the Precambrian time, the oceans and atmosphere formed around Earth, and the concentration of oxygen gas eventually reached the point where it could support aerobic _______. As the Earth cooled, layers formed as gravity pulled the dense material into the interior of the planet, creating a _______ of dense nickel and iron.

Answer 1

good answer should contain the following:

Precambrian

3.8

Pangea

life

core

Earth’s crust began cooling from the multiple meteor and comet collisions. Oceanic plates are denser than continental plates, but they are also much thinner. This means rift zones are more likely to form in oceanic plates than continental plates.

Step-by-step explanation:

from penn

Answer 2

Check below

Step-by-step explanation:

Precambrian

between 3.7 and 3.8

Pangea

respiration

layer/volcano