Monday, May 26, 2014


Salt Water and Fresh Water Science Experiments & Crocodile Folk Tales

Salt Water Crocodiles can live in both the salty ocean and freshwater rivers!  How do they do this?  How do salt and freshwater differ?  Learn more about the differences in salt water and fresh water with your preschoolers with these simple science experiments! Get ready for some fun waterworks with these science projects!

This experiment is perfect for young children because it introduces new concepts about how solutes (like salt) affect water and other variables.  It introduces a concept and allows your children to build on it by further investigation!

Simple Supplies:

* 3 clear cups
* water
* salt
* food coloring
* ice
* other variables (toothpicks, grapes, soap, etc)

Easy How-to:

1.  Put about one cup of water in each cup.

2.  Let your child dissolve 1-2 tablespoons of salt in two of the cups.  This is comparable to very salty ocean water.  (See note below.)

3.  Let your child squeeze some food coloring into the "fresh" water.  Watch how it spreads through the water easily and soon fills the entire cup.

4.  Let your child squeeze some food coloring into one of the salt cups.  Talk about how the differences you see in the salt and fresh water.

5.   What do you think would happen if you had fresh water on top of the salt water?  The best way to see this is to place an ice cube on top of the other salt water cup.  Give it about five minutes to melt.  Do not bump the cup! While you wait, read a crocodile story like the one below!

When the ice is significantly melted, you will have a little puddle of fresh water on top of the salt water.  Let your child squeeze some food coloring on top of the fresh/salt water cup!

Talk about how the food coloring stayed in the fresh water longer and took some time to spread throughout the entire cup.

6.  What other things could you test with your salt and fresh water cups?

My kids wanted to test grapes.  And guess what...with enough salt, a grape will float!  (When you add salt, you increase the density of the solution.  An item will float if it is less dense than the water it is in.)

7.  Crocodile Discussion:  Salt Water Crocodiles can travel hundreds of miles through the ocean, where they only have salt water to drink.  Salt water treats food coloring differently than normal water does, and it can cause problems if a crocodile (or any other animal) gets too much inside their body.  How do you think crocodiles handle the salt?  They actually have salt glands on their tongues that excrete the extra salt in their bodies!  

Gator Gumbo is a modern fable similar to The Little Red Hen, but with a Louisiana flair and an surprise ending!  

Note:  Ocean water averages 3.5% salinity.  This is just under 1 tablespoon  of salt per cup.  However, since 3.5% is an "average," and there are definitely portions of the water that are saltier, and the results are more visual, I recommend using closer to 2 tablespoons of salt in your cup.  :)

This post is part of the monthly Poppins Book Nook!  Each month bloggers choose a book based on a theme and share activities and science projects related to that theme.  This month the theme is folktales!  Check out these other great blogs for more folk tale science experiment and activity fun:

Enchanted Homeschooling Mom ~ 3 Dinosaurs ~ To the Moon and Back ~ Planet Smarty Pants ~ Farm Fresh Adventures ~ Growing in God's Grace ~ Chestnut Grove Academy ~ Learning and Growing the Piwi Way ~ The Usual Mayhem~ Preschool Powol Packets ~ Monsters Ed Homeschool Academy ~ Adventures in Mommydom ~ Teach Beside Me ~ Life with Moore Babies ~ Kathy's Cluttered Mind ~ Are We There Yet? ~ Our Crafts N Things ~ Hopkins Homeschool ~ ABC Creative Learning ~ Joy Focused Learning ~ P is for Preschooler ~ Laugh and Learn ~ A Mommy's Adventures ~ Inspiring 2 New Hampshire Children ~ World for Learning ~ Ever After in the Woods ~ Golden Grasses ~ Our Simple Kinda Life ~ A glimpse of our life ~ Journey to Excellence ~ Happy Little Homemaker ~ Little Homeschool Blessings ~ Simplicity Breeds Happiness ~ Raventhreads ~ Learning Fundamentals ~ Tots and Me ~ As We Walk Along The Road ~ Stir the Wonder ~ For This Season ~ Where Imagination Grows ~ Lextin Academy ~ The Canadian Homeschooler ~ School Time Snippets ~ Peakle Pie ~ Mom's Heart ~ A Moment in our World ~ Every Bed of Roses ~ Finchnwren ~ At Home Where Life Happens ~ Suncoast Momma ~ The Library Adventure ~ Embracing Destiny ~ Day by Day in our World ~ Our Homeschool Studio ~ A "Peace" of Mind ~ Thou Shall Not Whine ~ SAHM I am ~ eLeMeNo-P Kids ~ Simple Living Mama

Also, be sure to visit Enchanted Homeschooling Mom for a chance to win a folk tale curriculum bundle!  

Do you have any folk tale related blog posts?  We'd love to see what you're up to!  Please share them here:

I may share at any of these parties!


Suzanne said...

Is there anything else aside from food coloring you can use?

Carla at Preschool Powol Packets said...

Hi Suzanne! Food coloring is really easy to see/watch, but liquid watercolors may also work. If you really don't want to use any dyes, you may be able to color some water by blending up a strawberry or blueberry in a little bit of water until it is completely liquified. I haven't tried it, but it should work's just a lot more work. ;)