Organic compounds are made from: a. oxygen, carbon, and hydrogen b. carbon and hydrogen c. carbon and oxygen d. carbon only

Place the steps tor the formation of the enzyme pepsinogen in correct order

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

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?