This organism breaks down nonliving matter into energy-rich compounds giving it back to the soil is called a

A decomposer

Explanation:

An organism like a fungus or a worm breaks down dead, nonliving matter which ends up giving nutrients back into the soil.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

why is arctic sea ice important? arctic sea ice keeps the polar regions cool and moderate global climate. sea ice has a bright surface; 80 percent of the sunlight that strikes it is reflected back into space. as sea ice melts in the summer, it exposes the dark ocean surface.