Diego states that he has a scientific theory on why people yawn. How is he using the word theory incorrectly in a scientific context?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

The picture represents a structure of the respiratory system. which is the function of this structure? to bring air into the body to exchange oxygen with carbon dioxide to carry air to the lungs to release oxygen from the body

How do ratio scale and diagrammatic scale work