Q: Why did the atoms cross the road?
A: It was time to split!

Explanation: Ah, yes, this one reminds me of my first joke on this site.

Atoms are the building blocks of matter, of all things.  The element chart lists all the different types of atoms.

To split means to leave.  If I were watching a soccer game, at the end I might say, “Game’s over.  Let’s split.”  And then we would leave the park or the stadium where the game was being played.

When you “split an atom” you release a lot of energy, like in a nuclear bomb.

This joke is funny because it plays with two meanings of split.  Split also means to divide something into parts. If you are a gymnast you might know how to do the splits. You might even make a banana split.

Here is how atoms were first split: