Science
What is a Chemical Element?
A chemical element is a pure substance made of only one kind of atom — like gold, oxygen, or carbon. The 118 known elements are the fundamental building blocks of all matter, and they're organized by their atomic number on the periodic table.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains a chemical element.
Key things to understand
- 1An element contains only one type of atom, defined by its number of protons (the atomic number).
- 2There are 118 known elements, from hydrogen (1 proton) to oganesson (118).
- 3Elements can't be broken down into simpler substances by chemical reactions.
- 4They combine to form compounds — hydrogen and oxygen are elements; water is a compound of them.
- 5The periodic table organizes all elements by atomic number and shared properties.
Frequently asked questions
- What's the difference between an element and a compound?
- An element is made of one kind of atom; a compound is two or more different elements chemically bonded together. Oxygen is an element; water (H₂O) is a compound.
- How many elements are there?
- 118 elements are currently known. About 90 occur naturally; the rest have been created artificially in laboratories.
- What is the periodic table?
- It's a chart that arranges all known elements by atomic number, grouping those with similar chemical properties into columns so patterns are easy to see.