what is the difference between an element and a compound
An element is a pure substance made of only one kind of atom, while a compound is a pure substance made of two or more different elements chemically joined in a fixed ratio.
Quick Scoop: Core Difference
- Element : Only one type of atom, cannot be broken down into simpler substances by chemical means (for example, hydrogen, oxygen, gold).
- Compound : Two or more different elements chemically bonded together in a fixed proportion (for example, water H₂O, carbon dioxide CO₂, salt NaCl).
Think of elements as the basic “letters” of matter, and compounds as “words” made by joining different letters together in specific combinations.
Side‑by‑side snapshot
| Property | Element | Compound |
|---|---|---|
| Basic idea | Pure substance with only one kind of atom. | [9][1][5]Pure substance with two or more different elements chemically combined. | [1][2][5][9]
| Can it be broken down? | Cannot be broken into simpler substances by chemical methods. | [3][2][9]Can be broken into its elements by chemical reactions. | [2][3][9]
| Kinds of particles | One type of atom (all atoms have the same atomic number). | [5][7][1]One type of molecule, but that molecule contains different kinds of atoms. | [9][1][5]
| Composition | Just one element throughout. | [1][5]Elements present in a fixed ratio by mass (like 2:1 H:O in water). | [5][9][1]
| Properties | Properties belong to that single element (for example, oxygen is a gas, iron is a metal). | [2][9][1]Properties are usually very different from the elements that form it (water is a liquid even though hydrogen and oxygen are gases). | [9][1][2]
| How they’re represented | By symbols (H, O, Na, Fe, Au). | [2][9]By formulas (H₂O, CO₂, NaCl, NH₃). | [1][5][9][2]
| Number of types | About 118 known elements. | [3][7]No fixed limit; countless possible compounds. | [7][3]