A Pea in a Stadium: How Tiny the Nucleus Really Is

If an atom were stretched out to the size of a football stadium, its nucleus would only be about as big as a pea sitting on the fifty-yard line! Everything else inside that huge stadium would just be empty space with tiny electrons zooming around.

What an atom is and what is inside it What the nucleus is and where it sits Which two tiny particles live inside the nucleus Where electrons are found compared to the nucleus

Everything around you is made of atoms: your shoes, your dog, the water in your cup, even the air you breathe. Atoms are so small that millions of them could fit on the head of a pin. But even though atoms are tiny, they have parts inside them, just like a tiny toy can have small gears inside it.

Right in the center of every atom is a small, tightly packed ball called the nucleus. Inside the nucleus live two kinds of tiny particles called protons and neutrons. They stick close together in the middle, like two best friends huddled together, and almost all of the atom's weight comes from these two particles.

Way outside the nucleus, much farther away than you might think, tiny particles called electrons zoom around and around, super fast. If the nucleus is the pea in the middle of the stadium, the electrons are more like gnats buzzing near the very top seats. That huge empty space between the nucleus and the electrons is why atoms feel solid to us, even though they are mostly empty space!