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.

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Explanation:

Precambrian

between 3.7 and 3.8

Pangea

respiration

layer/volcano

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.

Explanation:

from penn

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.