This element makes up 78% of the earth's atmosphere, but animals cannot get it from the air. Animals must eat other organisms to get this element.

Which elements are found in ALL organic molecules?

Phosphorus can be found in which of the following molecules?

Name the element that is the most abundant (greatest number of atoms) in a living thing.

These two elements are needed to form water, the most common molecules in living things.

This element is needed so that red blood cells can carry oxygen to all parts of the body.

This element helps to build bones and teeth. It also helps in blood clotting after injury.

What types of molecules do not contain carbon or has carbon that isn’t bonded to hydrogen and is not used as an energy source?

What types of molecules contains both Carbon & Hydrogen and most important to living things?