Atoms & Elements

Everything is made of atoms

Pick anything around you. Your hand. A pencil. The water in your glass. Zoom in really, really far — way past what your eye can see, past what a microscope can see — and you'll find atoms.

Atoms are so small that about 5 million of them would fit across the width of one of your hairs. The whole world is built from them, like LEGO pieces too small to see.

A tiny solar system

Each atom has a heart called the nucleus (with little balls called protons and neutrons), and tiny electrons whizzing around it. A bit like the Sun with planets — except this whole "solar system" is so small you'd need 100 million of them stacked up to be 1 cm wide.

If an atom were the size of a football stadium, the nucleus would be a marble in the middle — and the electrons would be specks of dust along the edge. Atoms are mostly empty space! You and everything around you are mostly nothing — but the nothing holds together very strongly.

Each kind = an element

There aren't a million different atoms. There are only 118 — and almost everything you see is made from about 20 of them. Each kind is called an element, and each one has its own personality: hard or soft, shiny or invisible, safe or dangerous.

Tap any element to learn about it:

You are mostly oxygen and carbon

Your body is built from elements — like a recipe:

🔵 Oxygen — 65% (a lot of you is water, which has oxygen in it!)
⚫ Carbon — 18% (the LEGO block of all living things)
⚪ Hydrogen — 10% (also in water)
🟢 Nitrogen — 3% (in muscles, hair, blood)
🟡 Calcium — 1.5% (bones and teeth)
⚙️ Iron — 0.0007% (just a tiny bit — but it makes your blood red!)

That tiny iron is why you must eat iron-rich food (meat, spinach, beans). Without it, your blood can't carry oxygen properly. An atom you can't even see runs your whole oxygen delivery system.