Molecular mass

Molecular mass is like a way to measure how heavy a bunch of tiny things are when they stick together.

You know how you can count how many blocks you have and then see how heavy they are all together? It's kind of like that, but with really tiny things that you can't see with your eyes.

These tiny things are called molecules and they are made up of even smaller things called atoms. Just like how you can stack blocks on top of each other to make a tower, atoms can combine together to make a molecule.

Now, some molecules are made up of lots of atoms all stuck together, like a big tower of blocks. And some molecules are just made up of a few atoms.

So, when we talk about the molecular mass of a molecule, we are basically saying how heavy all of the atoms are when they stick together to make that molecule. It's like adding up the weight of all the blocks in a tower.

Scientists measure molecular mass in a unit called "atomic mass units" or "amu" for short. That's just a fancy way of saying how heavy the atoms are compared to each other.

So, the next time you play with blocks, remember that even tiny things like atoms and molecules can have their weight measured, just like your blocks.