Model Molecules

In science class, you have been learning how atoms join with other atoms to form molecules. You can't see molecules, but you can make models of them. A water molecule is made of two hydrogen atoms and one oxygen atom. In this activity, you and your family members will make models of water molecules.


Large and small marshmeallows held together with toothpicks.


To make a water molecule, ask an adult to help you use two small, colored marshmallows for the hydrogen atoms and one large, white marshmallow to represent the oxygen atom. Stick the marshmallows together with toothpicks so that one small marshmallow is on top and the other small marshmallow is on the side, as shown in the picture above.


How is your model like a real water molecule? Why do you think a large marshmallow was chosen to represent an oxygen atom, while a small marshmallow was chosen to represent a hydrogen atom?