Water is also called H20 since it has two hydrogen atoms (H) and one oxygen atom. Water molecules can cause water to have different properties such as solid, liquid and gas. The movement of the water molecules affect the form of water. If the molecules are moving very slow, it causes water to become a solid known as ice. If the molecules speed up, it could cause the water to be a liquid. When the molecules have an increase in kinetic energy, the water could become a gas and evaporate. Water molecules are important because water is needed by people, animals, and plants. People need water to drink and it is necessary for proper body function as well as animals. Plants also need water. Water covers about 71% of Earth which highlights it's relevance in our world.