What is the reason for the need of plants for chemical elements contained in the atmosphere (for example, nitrogen)?

The set of chemical elements from which the stellar, solar matter and living beings of the Earth are formed is practically similar. Four elements – hydrogen, carbon, nitrogen and oxygen – are widespread in the universe. The atmosphere, hydrosphere, lithosphere of the Earth contains atoms H, O, C, N. They form water (in liquid, solid and gaseous states), gases (nitrogen, oxygen, carbon dioxide) and various rocks and minerals. In living organisms, they are present in greater quantities than in stellar and solar matter. These are the main elements of living nature that are part of organic compounds.
Nitrogen is one of the most important elements for plant nutrition and the formation of chlorophyll, which plays an important role in plant photosynthesis. Nitrogen is part of the complex compounds that make up protein. Gives a green color to the plant, affects the growth of leaves and stems, prolongs flowering.

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