Atomic mass unit facts for kids

An atomic mass unit is a special unit of measurement. It helps us measure the mass of super tiny particles like atoms. Atoms are incredibly small, so we need a special way to talk about their weight.

What is an Atomic Mass Unit?

The atomic mass unit is often shortened to amu or just u. It's like using grams for everyday objects, but for atoms, we use amu. This unit helps scientists understand how heavy different atoms are.

How Much Does an Amu Weigh?

One atomic mass unit is about the same mass as a single proton or a single neutron. Protons and neutrons are tiny particles found inside the center of an atom. Electrons, which orbit the atom's center, are much, much lighter. So, their mass is usually not counted when we talk about atomic mass units.

The Dalton: Another Name for Amu

Sometimes, you might hear the atomic mass unit called a "dalton." This name is becoming more common. The unit is named after John Dalton, an important scientist from the 18th century. He was a naturalist and a teacher who did a lot of work with atoms.

Images for kids

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  Jean Perrin in 1926

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  Josef Loschmidt

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  Ball-and-stick model of the unit cell of silicon. X-ray diffraction measures the cell parameter, a, which is used to calculate a value for the Avogadro constant.

See also

In Spanish: Unidad de masa atómica para niños