Atomic mass

Atomic mass is like the weight of a very, very tiny Lego person! Every Lego person has a certain weight, and every atom (the building blocks that make up everything around us) also has a weight called atomic mass.

Scientists figured out the atomic mass by adding up the weight of all the parts that make up the atom - the protons, neutrons, and electrons. Protons and neutrons are found in the center of the atom, called the nucleus, and electrons zoom around the outside.

Different types of atoms have different atomic masses, just like how some Lego people are lighter or heavier than others. The atomic mass of an atom is usually given in a unit called atomic mass units, or AMUs for short.

So just like how a bunch of Lego people can weigh more or less than another group of Lego people, atoms can also have different atomic masses. And scientists can use atomic mass to help them understand how atoms behave and interact with each other!