Explain how scientists know the oxygen level in the atmosphere has changed because of plants. Could our atmosphere still be changing?

The chemical reaction by which plants produce complex food molecules (sugars) requires an energy input (i.e., from sunlight) to occur. In this reaction, carbon dioxide and water combine to form carbon-based organic molecules and release oxygen.

Explanation:

so basically plants create oxygen and If there were no plants on the planet we wouldn't be able to breathe.

and yes it could be changing since large quantities of trees are cut down every day in rainforests which produce large amounts of oxygen for us. hope this helps!

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.

2b2t

explanation:

2b2t