Facts for Kids

The electron is a tiny particle with a negative charge. It is one piece of every atom, the tiny building block of all things. Electrons are extremely light—about \( \frac{1}{1836} \) of a proton's mass—so they can move quickly inside atoms. In an atom, electrons whirl around the center called the nucleus, like planets around the sun.

How these electrons are arranged tells us what the atom can do. The shells around the nucleus hold them, and the outer ones, called the valence electrons, help atoms link up with neighbors in bonds. When atoms share or swap these electrons, they form substances we use every day, from metal spoons to water. So the electron helps shape the world.

People began to see atoms as not solid balls. They have a tiny center called the nucleus, and electrons whirl around it in shells, or orbitals. The nucleus holds most of the atom’s mass, while the electrons are spread out around it.

This idea helps explain chemistry: how atoms bond, how materials conduct heat and electricity, and why different atoms act the way they do. The arrangement of electrons, especially the outer ones, shapes an atom’s properties and its place in the world of matter.

The electron has a negative electric charge. Charge is a property that makes particles attract or push away from each other, like magnets. Opposite charges pull together, while like charges push apart.

All electrons carry the same size of negative charge, called the elementary charge and written as -e. It is the same amount of charge as a proton but with the opposite sign. Charge is a fixed, built-in property of the electron.

The electron carries a negative charge, and it is an elementary particle—one that we don’t know of a smaller part that makes it up. Its mass is tiny, about \( \frac{1}{1836} \) of a proton, so it is very light and quick.

Electrons behave as both particles and waves. They have a property called spin, a bit like a tiny spinning top, and the rule called the Pauli exclusion principle says two electrons cannot sit in exactly the same state at the same time. They also create electric and magnetic fields, which is how they influence other charged things around them.

Quantum ideas say that in the tiniest things, such as the electron, you can see both particle and wave behavior. Some experiments show a beam of electrons making interference patterns, just like waves, while other tests show them as tiny bits of matter.

Scientists use new ideas called quantum mechanics to describe how electron waves move near the nucleus and how their spins work. These ideas help explain why atoms have specific colors and shapes and how electrons fill up energy levels. It may sound strange, but it helps us learn more about the very small world. What other surprising tricks will electrons show us?

Mass tells how heavy something feels. An electron is the lightest charged lepton, which means it is extremely light compared with most things you see. In the lepton family, muon and tau are heavier friends.

A proton is about 1800 times heavier than an electron, so electrons zip around easily while protons stay heavier. Because of this small mass, electrons do not join in the strong force that glues nuclei, and they can move smoothly around the atom.

Electrons carry a built-in twist called angular momentum, or spin. This is not a big spinning top, but a property that lives inside the particle.

The spin is a special kind called one-half, written 1/2. When scientists measure it along a line, they get only two answers: up or down. That tiny spin also makes an electron act like a tiny magnet, which helps explain many things about atoms and magnets.

In the world of tiny things, the electron is a kind of particle called leptons. It’s very small and carries a negative electric charge. Some scientists think it’s one of the basic building blocks you can’t split into smaller pieces, like a single bead in a necklace.

Are electrons made of smaller parts? Scientists think many of them are fundamental particles—tiny building blocks you can’t break into smaller pieces.

That means the electron already comes with its own charge and spin, like a built-in toolkit. Even without parts inside, electrons act like tiny magnets because of their spin, giving them a magnetic moment that helps explain how atoms behave.

In the late 1800s, scientists started to look at mysterious rays coming from a hot part of a glass tube. Those rays moved in straight lines and could be bent by magnets, which meant they were charged particles traveling through empty space.

In 1897, J. J. Thomson proved these rays were tiny particles we now call electrons. They came from inside atoms and could roam outside matter when electricity moved through the tube. This showed that electrons are real pieces of matter that can be free, not just stuck inside atoms.