Screw the cap on the jar as tightly as you can. Slowly turn the jar upside down, then right side up again. You can just enjoy the sight, or read on to learn how chemistry makes your lava lamp flow. O is the formula of the water molecule , the smallest building block of water. Molecules are made of even smaller building blocks called atoms .
Every atom has an electrical charge.
The charge can be positive, negative, or neutral. This charge is the secret to how water behaves with oil. In a water molecule, the different kinds of charges are not spread out evenly. Instead, one part of the molecule has a mostly positive charge, and another part has a mostly negative charge. Molecules like this are called polar molecules.