<h2>Endothermic Process</h2>
Explanation:
An example of endothermic process is :
Heat is needed for water to boil.
Endothermic process can be defined as a process in which heat energy is absorbed from the surrounding that bring about changes in the molecular level like breaking chemical bonds, inter-molecular force of attraction etc.
Boiling of water is an endothermic process because during this process water absorbs heat , its kinetic energy increases and then it boils.
The correct answer is an accumulation of microorganisms in deep marine environments.
Chalk rock refers to a pure form of limestone produced in tropical and warm seas about 100 million years ago in the Cretaceous period. The microscopic marine algae known as coccoliths thrived in the ancient seas. Their shells were comprised of calcite. With the death of the algae, their bodies sunk to the floor of the sea and sediment of chalk got deposited.
Over many years layers of chalk sediment got deposited and resulted in compaction of loose sediment into solid chalk rock.
I believe the correct answer is upwelling. Lets say we have producers such as plankton. well upwelling currents bring dead matter from the ocean floor up to the surface, creating plankton.