Water is all around us and extremely important to life! Have you ever thought about what makes water so different from all other compounds?

Image is of a water bottle and a glass of water
Image is of a beach and ocean

Let’s start by reviewing the basics of water—its formula and shape.

Interactive exercise. Assistance may be required. Drag and drop the elements to make the correct chemical formula for water.

Great job! This is the chemical formula for water.

Next, build the structural formula for water.


This activity might not be viewable on your mobile device. Interactive exercise. Assistance may be required. Click here to build the ball and stick model and the space filling model of water.

Build a Molecule
Click to Run

As you can see, there is not one "best model." Each model has its advantages, and each model has limitations. Which model is the "best" depends upon what information you are trying to obtain.


The bonds between hydrogen and oxygen and the shape of the water molecule greatly influence its unique role in our world. Covalent compounds share electrons between atoms to form a bond. However, hydrogen and oxygen do not share equally. Continue to the next section to find out what happens when electrons are not shared equally between atoms.