An element is a pure substance made of only one type of atom, one that cannot be broken down into anything simpler; compound, by contrast, is an adjective describing something made up of two or more parts or elements combined. A memory hook: oxygen and gold are elements on their own, while a compound word such as "toothbrush" is made of two separate parts joined together.
The core difference
An element is a single, basic substance, while compound describes something made up of two or more parts or elements combined rather than naming a substance on its own.
- element — a substance made of only one type of atom, which cannot be broken down into simpler substances: Oxygen and gold are both chemical elements.
- compound — made up of two or more parts or elements combined: "Toothbrush" is a compound word.
How to tell them apart
Element comes from the Latin elementum, meaning a first principle or basic building block, which fits its chemistry sense neatly: elements are the basic units everything else is built from. Compound has a more tangled history, possibly from the Malay kampung, meaning a group of buildings or village, reshaped over time by the unrelated English sense of "to combine", from Latin componere.
Both words also carry meanings outside chemistry. Element can mean a basic part of anything, such as trust being a key element of a relationship, or the heating part inside an appliance. Compound can mean a fenced area containing a group of buildings, a verb meaning to combine ingredients into one substance, a verb meaning to make a problem worse, or, in finance, to calculate interest on both an original amount and the interest already earned.
