It never was - Nitrogen is the "major gas".
Heterotrophs require oxygen as the essential atmospheric gas for cellular respiration, which is the process that generates ATP (energy) for their metabolic activities.
carbon dioxide
Oxygen is the major atmospheric component that is chiefly a product of life processes, produced mainly through photosynthesis by plants and other photosynthetic organisms.
Banded iron formations were caused by the production of oxygen gas. The iron in these formations reacted with the oxygen in the ocean, forming insoluble iron oxides that settled to the seafloor. This process played a crucial role in the Great Oxidation Event, increasing atmospheric oxygen levels.
Oxygen gas (when we exhale, we breathe out carbon dioxide).
Oxygen is the atmospheric gas that is produced as a by-product of the light reaction of photosynthesis and is essential for aerobic respiration in organisms. Oxygen is used in cellular respiration to break down glucose and produce ATP, providing energy for various cellular functions.
oxygen
Most plants release some oxygen from atmospheric carbon dioxide.
There are many different ways to calculate the moles and grams of oxygen. but one mole of oxygen is always gonna equal 32 grams because its diatomic, meaning it only comes in nature as O2. so it would be the atomic mass of oxygentimes 2. 16*2= 32
Oxygen is the major gas that is the cause chemical weathering.
because most combustible gas meters are oxygen dependent and will not provide reliable readings in an oxygen deficient atmosphere
Oxygen is the most important atmospheric gas for human survival. It is essential for cellular respiration, providing the energy needed for our bodies to function properly. Without oxygen, we would not be able to survive.