The Water Cycle for Middle School Science

2 days ago

3 min read

The water cycle is a topic that kids learn about throughout elementary and middle school. The basic ideas stay the same, but the vocabulary gets more complex as students get older. The picture book below is helpful for both elementary and middle school students learning about the water cycle.

The Water Cycle

You may also want to share information on the water cycle in a reading passage. You can purchase this printable reading passage and the accompanying comprehension activities at Teachers Pay Teachers.

The Water Cycle

The water cycle shows how water travels through the atmosphere, hydrosphere, geosphere, and biosphere on Earth. Water can be found in all three states of matter on Earth. The three states of mater are liquid, solid, and gas. This means that water can look very different in different places.

There is no first step in the water cycle. It is constantly being repeated with no beginning and no end.

When water falls from clouds, it is called precipitation. Water can fall anywhere on Earth, including on land or in bodies of water. Most precipitation falls in the oceans that cover 70% of the world.

Water that falls into lakes and oceans stays there while water that falls of land or in a stream or river is always on the move. Water that falls on land will always flow downward toward larger bodies of water. The water either flows along the ground as surface runoff, or it will soak into the ground and flow underground as subsurface runoff. Eventually, most of the water will make it to a larger body of water.

Some water that falls as precipitation will be absorbed by plant roots. The plants use some of this water in their cells and tissues and during photosynthesis. Some of the water is released back into the sky as water vapor. The water vapor escapes through the plants’ leaves in a process called transpiration.

Meanwhile, water is constantly being evaporated back into the sky as water vapor. Water vapor is a gas. About 80% of evaporation takes place in the oceans, but you can observe it happening within a puddle on the sidewalk as well. Evaporation is simply the process of liquid water turning into water vapor.

When the air is warm, it carries the water vapor as it rises in the sky. As the air rises, it cools. Warm air can hold more water vapor than cold air, so high in the sky, the water vapor condenses back into liquid water. Condensation can happen anywhere. It happens in the sky when clouds form. It happens near the surface of the Earth on foggy days, and it happens on the outside of a cold glass in the summer.

High in the atmosphere, tiny drops of water evaporate again quickly, but when the drops of water collect on a small piece of dust in the atmosphere, they grow large enough to stay liquid. Scientists call these small particles condensation nuclei because they are the beginning of clouds.

The clouds grow larger and heavier as they collects more water droplets. Despite being extremely heavy — an average cumulus cloud can hold over one million pounds of water — clouds float in the sky because they have a large amount of surface area and the rising warm air pushes up against them. Inside the clouds, water droplets join together until they are too big to float in the sky and fall out of the cloud as precipitation.

The sun drives the water cycle. Heat from the sun gives liquid water the energy it needs to evaporate and become water vapor. Heat from the sun also warms the air that carries the water vapor high into the atmosphere. Without the sun, we wouldn’t have a water cycle on Earth.

Understanding the water cycle is just one part of learning the steps in the water cycle. Students also have to practice remembering the vocabulary and the information. Flashcards are incredibly helpful for this task. Printed and digital flashcards make a great addition to your classroom routine. You can get these flashcards on the water cycle at Teachers Pay Teachers.