🧂 Element or Compound — What’s the Difference?
7th Grade ⚗️ Chemistry
An element is made of just one kind of atom. A compound is made of two or more kinds of atoms joined together.
Elements
Gold, oxygen, iron and carbon are elements — each contains only one kind of atom. All the elements are arranged in the periodic table.
Compounds
Water is a compound: each molecule has two hydrogen atoms and one oxygen atom (H₂O). Table salt is a compound of sodium and chlorine (NaCl).
A new substance
A compound can be totally different from its elements. Sodium is a metal that reacts wildly with water, and chlorine is a poisonous gas — but together they make the salt you sprinkle on fries!
Quick quiz
Which is an element?
What is the formula for water?
Where are all the elements listed?