The process by which plants and animals release stored carbon back into the atmosphere is called

respiration.
diffusion.
photosynthesis.
extraction.

Respiration

Explanation:

The carbon exchange between plants and the atmosphere takes place via:

1) Photosynthesis

2) Respiration

Photosynthesis is a process in which the plants take in carbon in the form of CO2 and water and convert it into glucose along with the release of oxygen (O2). The entire reaction requires energy in the form of sunlight.

Respiration, in contrast involves the breakdown of glucose in the presence of O2 to the release the carbon back in the form of CO2, along with the formation of water and energy.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !