Which explains why oxygen was absent from earth’s early atmosphere?
excess heat converted atmospheric oxygen into other gases

oxygen chemically combined with newly formed rocks. photosynthesizing organisms such as plants had not yet appeared. volcanic gases suppressed the natural production of oxygen

The reason why oxygen was absent from Earth's early atmosphere is excess heat converted atmospheric oxygen into other gases. Therefore, the correct answer to the above question is option A.

Explanation:

Oxygen is a most abundant gas of the atmosphere. Oxygen occupies 21% of the total share of the gases that is present in the atmosphere of earth. All the living animals and aquatic animals take oxygen for their life to happen.

Green plants are the only source of conversion of carbon dioxide into oxygen. Oxygen is carried in human body by the blood throughout the whole body. Due to the presence of oxygen in air are very animals and plants living on the earth

Oxygen chemically combined with newly formed rocks

Explanation:

At the start of the universe, oxygen was produced as by products of photosynthesis by cyanobacteria. Rocks contained a mineral called olivine that combined rapidly with oxygen in the presence of water thereby removing oxygen from the earth's atmosphere.

However, as the earth crust evolved to a composition more like what we have today, olivine virtually disappeared. In the absence of that mineral to react with water and consume oxygen, the gas was finally allowed to accumulate in the earth atmosphere. Oceans eventually became saturated, and oxygen crossed into the atmosphere.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.