Atoms

matter · science · tiny · structure

Super tiny builders. Atoms are so small you could fit millions of them on the head of a pin. They're the basic pieces that make up every chemical element and everything in the world.

Nucleus and electrons. Every atom has a tiny center called a nucleus packed with protons and usually neutrons. Around this nucleus, electrons zoom in an electromagnetically bound swarm, like planets orbiting the sun.

Protons tell the story. The number of protons in an atom's nucleus determines which element it is. Sodium always has 11 protons, copper always has 29 protons, and this rule never changes.

Isotopes are cousins. When atoms of the same element have different numbers of neutrons, they're called isotopes. They're like twins with slightly different traits but still part of the same family.