Okay kiddo, do you remember when you blew up a balloon and then let it go and it floated up into the air? That's because the balloon was filled with helium gas!
Now, helium-3 is a type of helium gas that's a bit different from the regular helium you might be familiar with. It's extra special because it can be used in machines called "neutron detectors".
But, before we can talk about why helium-3 is so important, we need to learn a bit about atoms.
Everything around us is made up of tiny little building blocks called atoms. Atoms are like really, really small LEGO blocks that can be stuck together in different ways to make everything we know.
Helium-3 is a type of atom that has two protons and only one neutron. But, to really make sense of that we need to talk about the tiny little pieces that make up atoms, called protons, neutrons and electrons.
Protons are super important building blocks that are found at the center of every single atom. They have a positive electrical charge and help to hold the atom together.
Neutrons are also found in the center of atoms but they don't have any charge at all. They help to add a bit of extra stability to the atom.
Finally, electrons are teeny tiny little pieces that orbit around the outside of the atom. They have a negative charge and help to keep the atom glued together.
Now, back to helium-3! Because helium-3 is a bit different from regular helium, it can be used in special machines that are designed to detect these tiny neutrons we talked about earlier.
These neutron detectors are used for all sorts of things, from finding out more about the inside of the earth, to making sure that nuclear power plants are working safely.
So, to sum it all up: helium-3 is a special type of helium that can be used in machines called neutron detectors to help us learn more about the world around us!