Making Molecules

Everything in the world is made of tiny building blocks called atoms. But atoms don't usually like to be alone! Most of the time, they 'hold hands' with other atoms to form groups. When two or more atoms stick together, we call that group a molecule. The 'handshake' that keeps them together is called a chemical bond. Think of atoms like individual LEGO bricks and molecules as the small shapes you build by snapping those bricks together.

Molecules can be made of the same kind of atoms or different kinds. When two atoms of the same type join, like $O + O$, they make a molecule of that element. But atoms can also team up with different neighbors! For example, when two Hydrogen atoms ($H$) join one Oxygen atom ($O$), they create a molecule of water, which we write as $H_2O$. Whether the atoms are twins or totally different, as long as they are bonded, they are a molecule.

A molecule is the smallest part of a substance that still acts like that substance. Imagine a sugar cube. If you crush it into dust, it still tastes like sugar. If you could zoom in and find the tiniest possible speck of that sugar that still tastes sweet and acts like sugar, you would be looking at one single sugar molecule. If you were to break that molecule apart into its atoms, it wouldn't be sugar anymore—it would just be a pile of Carbon, Hydrogen, and Oxygen atoms!