A compound
In literally every single thing in the universe. Elements are the very building blocks of things. Compounds are things that are made up of more than two elements. If something is made up of two Oxygen molecules, it is not a compound. If something is made up of an Oxygen molecule, and a Carbon molecule, it would be a compound.
A compound is something that is made up of two or more different elements or units.
Any substance made up of two or more elements chemically combined is a compound.
A compound is made up of two or more different elements that are chemically bonded together. Each compound has a fixed ratio of elements and distinct properties different from its individual elements.
Iron is, itself, and element. It is not a compound of two elements.
A molecule of water, which has the formula H2O, is made up of the elements hydrogen and oxygen.
Copper carbonate is made up of the elements copper, carbon, and oxygen.
In chemistry, a "compound" is a substance made up of two or more elements in chemical combination.
Compound
A compound is made up of two or more elements (water is a compound, made up of two elements: oxygen and hydrogen).
A molecule made up of two or more different elements is called a compound, whereas a molecule made up of two of the same elements is still just an element.
Elements are single, however compounds are made up of two or more elements.