The atom that is most closely associated to living things is carbon or nitrogen

the atom that is most closely associated to living things is carbon

Carbon

Explanation:

Carbon is associated with living beings by participating in the metabolic needs of these organisms, being the chemical basis for the essential molecules (such as proteins, carbohydrates and lipids) of living things.

Carbon is also present in the photosynthesis reaction of plants, where the sun's energy reacts with carbon to generate oxygen.

In addition, carbon is present in many foods, particularly carbohydrates, which when eaten by animals, are converted into energy to help them stay alive.