Tag Archives: water science

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In honor of World Water Day tomorrow (March 22, 2014) we have Water Can Be . . . by Laura Purdie Salas and illustrated by Violeta Dabija. For more information about the book, see the review at our sister blog, Wrapped in Foil.

water-can-be

Water Can Be... is perfect for World Water Day because Laura Purdie Salas has pledged to donate 10% of her royalties on this book to WaterAid.org, an organization that helps bring clean water and improved sanitation to areas that lack it.

waterAid-WorldWaterDay

Not only does the book help a charity, but it also is likely to be an inspiration for STEM-related activities.

At first glance, it might seem to be too lovely to be a serious science book.

Water can be a…

Thirst quencher
Kid drencher
Cloud fluffer
Fire snuffer

As you spend more time with the book, however, you begin to discover the depth Salas has incorporated into it. The back matter has "More About Water" with explanations for each phrase in the main text. In it Salas introduces children to such scientific vocabulary as "condense," "water vapor" and "water cycle." She explains how all living organisms need water to live, how it regulates temperature and how it can be a powerful natural force. It is sure to generate discussion and even more ideas about the importance of water.

Water Can Be... could be used to learn about the seasons, weather, the importance of water to living things, and even life cycles. Today, however, we are going to concentrate on water quality issues for World Water Day.

Science activities inspired by Water Can Be...

1. Water filtration experiments - modeling a real world event

In January 2014, there was a chemical spill into the Elk River of West Virginia (Wikipedia report). Residents of several localities that use the river as a source of water were told not to drink, cook with, or bathe in the contaminated water. How did the water treatment plant go about removing the chemicals from the water?

Water treatment plants use a variety of steps to clean water, but the most common are disinfection (using ozone or ultraviolet light, for example), coagulation (clumping contaminants so they are easier to remove), sedimentation (allowing contaminants to settle to the bottom), and filtration. Today we are going to concentrate on filtration.

One of the chemicals that was spilled into the water in West Virginia was reported to smell like licorice, which is how the spill was first noticed.  Let's model this real world event by adding some licorice candy to water and then try to remove it again.

licorice

Note:  remind children to never eat or drink their science experiments! Just because the experiment involves food, doesn't mean it is safe to consume.

Gather:

  • Small colander or similar device
  • Coffee filters
  • Cheesecloth or similar material (optional) Note:  paper towels are generally too absorbent to filter properly
  • Clear plastic cups
  • Clear jar with lid
  • Licorice candy
  • Water
  • Activated carbon

Note: You can obtain activated carbon from most aquarium supply stores. The carbon is used in aquarium filters.

Step 1. Add a few pieces of licorice to roughly two cups of water and let it set overnight in a covered jar.

What happens?

filtration-over-nightAsk the children to examine the contents of the jar and see what changes occurred. Has the color of the water changed? What about the smell? Has the licorice changed? Remove a piece and compare it with a fresh piece of licorice.

Explain that the licorice contains sugars, artificial colors, and other ingredients that are soluble in water.

The licorice I used contained palm oil, which formed a skim at the top of the water (thin darker red band). If your candy also contains oil, see if the children notice a similar layer. If they do not notice, you can point it out to them.

Step 2. Pour about half the liquid and a few pieces of soaked licorice into a plastic cup or glass. Set this aside so the children can compare their results later.

Step 3. Ask the children how they would remove the licorice from the water.

One way would be to filter the water.

Set up a colander. Line it with a coffee filter and some cheesecloth or similar material. Place the colander over a plastic cup or small bowl to catch the liquid.

filtration-setup

Pour the remaining liquid and licorice through the colander.

What does the resulting liquid look like? What does it smell like?

filtered-versus-not

The filtered water should be lighter colored (left), but it still will likely contain sugars, colorants, and smell like licorice.

Step 4. How can you remove even more of the contaminants?

activated-charcoal-111

Activated carbon is said to remove toxins, odors and discoloration from water. Will it help?

Clean the colander and replace the coffee filter with a new one. Add a layer of activated carbon to the bottom over the filter. The amount will vary with the size of your container, but try to add enough that the contaminated water must flow through the carbon. Rinse the activated carbon with clean water for several minutes to remove all the accumulated dust. Otherwise your sample will look like the one on the left, below:

charcoal-filtered

After the carbon has been washed, pour the sample you previously filtered through the carbon in the colander and collect it in another clean, clear container.

filtration-right-charcoal

What does the water look like now? How does it smell?

What would happen if you filtered it again? Do you think more of the licorice would be removed? Do you think it is possible to remove all of the chemicals from it?

Depending on what age children you are working with, you could take it to the next level with a more complicated water filter.

This video from Home Science Tools shows how to make a water filter using a large soda bottle. It uses coarse sand, fine sand and pebbles. See full instructions at their website.

You could also add activated carbon to this filter.

Extension:  If you search around the Internet, you will find some filters that layer the ingredients in the order:  Sand at the bottom, pebbles in the middle and charcoal on top (to receive the water first). Other filters show that charcoal on the bottom, the pebbles in the middle and the sand on top. Which way do you think will work best? Why? Now build two filters, one each way, and compare them.

The Water Project website has more links to Water Pollution and Filtration Science Experiments for Kids.

2. Using STEM to help people gain access to better quality drinking water.

According to WaterAid, women in developing countries walk an average distance of 4 miles each day to gather water for their families use. A typical can of water that these women carries weighs 40 pounds (5 gallons x 8 pounds/gallon). The water they gather is also often dirty and may contain disease-causing organisms. How can STEM help?

In one example, an engineering student at Arizona State University has come up with a way to allow women to carry more water more easily, plus the water is cleaned and disinfected during transport. The new invention is called Safe SIPP. You can see more about it in the video below. Note: you might want to preview the video before showing it to sensitive children because it does talk about how unsafe water results in children dying.

 

 

Want to learn more about water? The American Chemical Society has a The Wonder of Water activity guide to download at the website (see right sidebar on the page for link). Visit the archive as well for another activity guide, Water in Our World.

Let's not forget Water Can Be . . . (Millbrook Picture Books)., a little book with a huge message about the importance of water that inspired our post today.

Ages 5-8
Series: Millbrook Picture Books
Publisher: Millbrook Pr Trade (April 1, 2014)
ISBN-10: 1467705918
ISBN-13: 978-1467705912

Disclosures: This book was provided electronically for review via NetGalley. Also, I am an affiliate for Amazon, and if you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.

 

Come visit the STEM Friday blog each week to find more great Science, Technology, Engineering and Math books.

Once children have begun to be aware of how important water is to our planet and to living things, it is time to investigate how water recycles.

the-water-cycle

Our post today was inspired byWater Cycle (Pebble Plus: Earth and Space Science) by Craig Hammersmith, which is a picture book that introduces many important concepts and vocabulary words pertaining to the water cycle, such as evaporation, condensation and precipitation. Along with a glossary and an index, there are instructions for making a "mini-earth" in the form of a terrarium. (A review copy of this book was provided by the publisher, Capstone.)

The first step to understanding the water cycle in understanding the states of matter. Water is an ideal substance to study because it exhibits three of the four states of matter (solid, liquid, gas) at relatively normal temperatures.

Solid Water (ice, hail, snow):

Gather:

  • Plastic tubs of different sizes, food molds, ice cube trays, clean milk cartons, etc.
  • Access to freezer
  • Water
  • Food coloring (optional)
  • Spray bottle (optional)
  • Springs of herbs, flower petals (optional)

Put some water in different-shaped containers and freeze it. Allow the children to help pick containers and fill them. For added enjoyment, add a few drops of food coloring to the water. Or you can add bits of edible flowers such as roses, or leaves of herbs as decorations. Explain that the liquid water is going to become solid.

On a warm day, take the ice outside and use it to build ice sculptures. Remove the ice from the containers by briefly immersing in water if it won’t just slip out. If you don’t have time to make special shapes, simple ice cubes can work great for this, too.

Have the children pile the ice to make buildings, animals or abstract forms. You can lightly mist the finished products with water containing food coloring. Then watch the sculptures melt. Predict how long it will take. Explain that the solid water is becoming liquid water by melting.

Older children can design inventions to protect the ice from melting, and then build and test their invention by seeing how long it takes for the ice to melt inside the device versus unprotected.

(See a previous post about snow science, too.)

icicles

 

Liquid Water:

Learning how to make a water siphon is a fun and useful way to learn about some of the properties of liquid water.

Gather:

  • Small amount of tubing, such as clear plastic aquarium tubing - about 18 to 24 inches long
  • Water
  • Two bowls or other containers large enough to hold tubing submerged, or even a large glass and a sink
  • Food coloring (optional)

Fill one of the containers with water. Add a few drops of food coloring (optional). Submerge the tubing under the water and jiggle to remove air bubbles until the tube is filled with water. Place your thumb tightly over one end of the tube and move it to an empty container, ideally slightly lower than the first. Release your thumb and the water should start moving from the filled bowl to the empty one via siphon action. It may take some practice if you have never done it before.

You can also put two straws together to use instead of tubing, as shown in the first video (Note: there is a pop-up ad):

 

The video below by Doctor C shows how a siphon works using a chain model. (Note:  The narrator takes a sip of the water at the end. You might want to turn the video off before you reach that point to prevent copycat behavior.)

 

For older children, time how long it takes to fill a container of known size and calculate rate of flow. Figure out how long it would take to empty a ten gallon fish tank with your siphon. How about an average swimming pool?

pool-water-texture

(Pool Water Texture by Petr Kratochvil)

Water as a Gas
:

To study water in the gas form, you will need water, paint brushes and a sidewalk or driveway on a hot day. If you must stay indoors, a chalkboard will work too. Simply paint the water onto a flat surface and then time how long it takes to evaporate. Explain that the liquid water is turning into a gas as it disappears and is rising up into the air. That is called evaporation.

To show the gas water turning back into liquid, set out a glass full of ice water on a warm day. The gas should condense into liquid around the outside of the glass after a few minutes, creating droplets. This is called condensation.

Water_cycle

The USGS has child-friendly information about the water cycle, including a printable poster.

If you would like to make a terrarium as a model of a water cycle, see our previous post.

See how a man kept a plant in a bottle for years without adding water or air (Note:  website has numerous ads and images that might not be child-appropriate).

You could spend a lifetime studying water. Next week we're going to find out where the the water in your home faucet comes from and how it gets to the tap.

Water Cycle (Pebble Plus: Earth and Space Science) by Craig Hammersmith

Age Range: 4 and up
Publisher: Capstone Press (August 1, 2011)
ISBN-10: 1429671424
ISBN-13: 978-1429671422


Disclosures: The book was provided for review purposes. Also, I am an affiliate for Amazon. If you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.

 

Come visit the STEM Friday blog each week to find more great Science, Technology, Engineering and Math books.

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Summer is a fantastic time for kids to learn about water through books and hands-on activities.

Water is essential for life, yet we tend to take it for granted because it is generally so readily available. Over the next few weeks, we will use children's books to explore the water in different ways, including why it is important, the water cycle, and water in our homes.

Today's post will help children become aware of how important water is to living things and all the ways that it is used.

why-living-things-need-water

Our lesson was inspired by Why Living Things Need Water (Acorn: Why Living Things Need) by Daniel Nunn, an informational picture book for the youngest set illustrated with bright color photographs.

Activity 1. Brainstorm how humans use water, creating an age-appropriate list. Either make a collage out of photographs from magazines showing the ideas or have the children create their own illustrations.

Preschool examples:  Drinking, bathing, cleaning up

Grade school examples:

Water is used for...

  • Drinking
  • Bathing
  • Washing/cleaning
  • Cooling off
  • Heating (some homes)
  • Cooking
  • Growing food
  • Swimming
  • Painting and creating art
  • Boating and skiing on (recreational activities)
  • Getting rid of wastes
  • Making electricity
  • Transportation of goods
  • Putting out fires
  • Making products like paper and steel
  • etc.

sailboatPeople have used boats and water to get from place to place for ages.

High school biology examples:

Within our bodies we use water:

  • To regulate internal temperature
  • To move nutrients
  • To move oxygen
  • To move hormones and other chemical signals
  • As a medium for chemical reactions
  • To remove wastes

Did you know that the lungs must be moist to work properly?

 

 Activity 2. Investigate how animals use water by putting out a bird bath.

Make or purchase a bird bath. The style will depend a bit on the type of birds that commonly visit bird baths in your area. According to the Audubon Society, the ideal bird bath should contain no more that two inches of water and should have variable depths so birds can walk in and out.

Once you have it set up, record what types of birds visit and what they use the water for.

You might see some birds drink water, like the owls in this video.

Many living things use water to help keep cool. My sister and her family had a hawk lay in their bird bath on a hot day, soaking the water into its feathers.

bird-bath

This robin is using a pool of water to take a bath in. Why might it be important for birds to take a bath?

Certain types of birds, such as grackles, have been known to wash their food and other objects in a bird bath.

Birds like ducks and geese use water for protection. If a land-based  predator comes by, they can simply swim away. They also use water for transportation, by swimming from place to place in it to find food and nest sites.

Make this activity an experiment by:

  • recording the number and species of birds visiting throughout different times of the day
  • comparing bird visits to different styles of bird baths

 

You also might want to visit a pond, lake or ocean and observe all the living creatures that use water for a home.

Activity 3. Water use by plants

We all know we must water our houseplants, lawns, and gardens, but what are plants doing with the water?

Primarily, the plants have chemicals in their leaves that can use sunlight, water, and carbon dioxide to make food in the form of sugars. This is called photosynthesis.

Plants also use water to move nutrients, to add support to their structures, and to keep cool.

Gather:

  • Clear plastic bag big enough to hold a few leaves
  • Twist-tie or chenille
  • Tree or shrub (with leaves close enough to the ground to put a bag over)

On a warm sunny day, slip a clear plastic bag over some leaves on the end of a branch of a tree. Tie the bag tightly to the branch with the twist-tie or chenille, trapping the leaves inside and preventing air from escaping. Visit the tree in fifteen minutes and then again in a half hour. What is happening inside the bag?

plant-transpiration

You should see the bag start to fill with condensing water. Trees release a lot of water on a hot day through a process known as transpiration. You are capturing the water that is being released. Some figures suggest that more water enters the air from plants than from the surface of the ocean.

Transpiration cools the plant on a hot day and is also involved in helping the plant move water.

How to make this activity an experiment:

  • compare the rate of transpiration at different times of the day or at different temperatures (by measuring the amount of water produced in a given time)
  • compare transpiration rates between different trees and shrubs

Overall, we have seen that water is necessary for life. Next week we'll look at how water is moved through the water cycle.

Why Living Things Need Water (Acorn: Why Living Things Need)
by Daniel Nunn

Reading level:  Prek-1
Hardcover: 24 pages
Publisher: Raintree (March 1, 2012)
Language: English
ISBN-10: 1406233757
ISBN-13: 978-1406233759

The book was provided by the publisher for review purposes.