Sent in by:
Katie of Preston, WA and Jim of AZ
Some science that's sure to float your boat.
- 2 eggs
- liquid soap
- cooking oil
- balance scale
- Check with an adult before you begin.
- Fill a glass half full with water. Place an egg into the water. The egg will sink because it is more dense than the water.
- Start adding salt to the water one tablespoon at a time. Help the salt dissolve by stirring it into the water. What happens? How much salt do you have to add to get your egg to float?
Ready for us to float the science scoop? Adding salt to the water squishes more molecules into the water. This makes the water more dense. When there was no salt in the water, the egg was more dense than the water and it sank. Adding salt to the water makes the water more dense than the egg which makes the egg float. If you weigh a cup of saltwater and a cup of fresh water, the saltwater will weigh more than the fresh water even though it is taking up the same amount of space (a cup). This is because the saltwater is more dense than the fresh water.
Design your own experiment by thinking of a question you'd like answered. Would sugar dissolved in water make an egg float? How about soap or oil? Make a prediction, test it out and send your results to ZOOM.
Karia, age 11 of Gilbert, AZ wrote:
it work because it was a different kind of egg floating but it still worked... what happened was I put the salt in the fresh water and put the egg in and it WOrKED!!! its so cool
Grace, age 12 of Washington, D.C. wrote:
the salt water egg floated and the plain water egg didn't
Nimra, age 9 of New York wrote:
well I only did one egg and a glass last 6 tablespoons of water that way is much easy. also it is much faster floating egg.
Anthony & Veronica of Maryville, TN wrote:
the egg sunk in oil. it was also sticky
well it went at the bottom and middle then top it was so cool.
Gabriel, age 7 of Denver, CO wrote:
the egg really float when I adding salt to the water thats was a lot of salt
Molly, age 6 of Bristow, VA wrote:
it was fun. and it was cool. The egg flated in the salt water but not in the sugar water. The egg was more dense in the sugar water.
Mariah, age 12 of Dallas, TX wrote:
I just couldn't belive that it floated. I had to add alot of salt to make it float but... it actually floated!!!
Jess of NC wrote:
It was foating after 3 tablespoons but I did it in a 16 oz cup.
Grant, age 7 of Coral Springs, FL wrote:
when we put lots of salt, five spoons, in the water, it floated
3rd Grade, age 8 of Agoura Hills, CA wrote:
Our class tested salt and sugar. We found out that it takes a lot more sugar to float the egg than salt. Now we're trying to learn why.
Tierany, age 8 of Jonesboro, AR wrote:
When I added 4 spoons of water the egg stayed afloat because it was more dense.
Yuri, age 14 of Tallahassee, FL wrote:
the egg dont float in water because the egg is more dense then whater, the egg only float in different liquids that more dence then the egg.
Joseph, age 11 of Ocala wrote:
The saltwater was more dense than the freshwater.
Maria, age 11 of Sherman, TX wrote:
At first it didn't work but when I kept adding more and more salt (about 10 tablespoons of salt or even a little more) it worked!!! That was so awesome my project is gonna rock!
Axel of Taylor Lake Village, TX wrote:
The egg floated a little bit with two tablespoons of salt but floated better with three tablespoons.
Meredith, age 8 of Winston Salem, NC wrote:
I tried the experiment with an uncooked egg and a hard-boiled egg and both floated in the salt water.
Chang, age 10 of Shengyang,China wrote:
We put salt in and the egg floated we put liquid soap in another and the egg didn't float.
Meccayla, age 11 of Phoenix, AZ wrote:
The egg was in the middle with the sugar and with the salt it went to the top of the cup.
Hannah, age 8 of King, NC wrote:
When I did this it took it least 5 tablesppons to float the egg, I tested five eggs! 3 ot of 5 took five tble. spoons.
Shakira, age 12 of Baltimore, MD wrote:
we had put a egg in the reagular water with out salt water. it did not float at all so we had put another egg in the salt water and the egg had float. the only reason that the egg had floated in the salt water not in the reagular because the salt water had more boncey then the reagular water. thats why it had floated in the salt water not the reagular water.
Angerica, age 10 of The Philippines wrote:
When the egg is put on the tap water it sank but when I put the egg in the water with salt it floats. I think this is not true but when I try it I can't believe it.
Jessie, age 10 of New York, NY wrote:
at first the egg did not float and I added a couple tsp. of salt and stured and I could not belive it. it had actually worked.
Lali, age 10 of West Linn, OR wrote:
Well, I got a measuring cup, poured a lot of salt into the cup and it sank! then I added 2/3. 1/3+2/3=1/1.
Max, age 10 of Playa Del Rey, CA wrote:
I used 1 cup of water and 1 tablespoon of salt and the egg floated to the top. It was the shortest experiment I ever did.
Myana, age 10 wrote:
I said wow because didn't know that the egg will float.
Ayla, age 7 of Chicago, IL wrote:
We tried epsom salts water, and salt water, and other liquids, like milk and Dr. Pepper. The egg floated in the epsom salts water too. It was cool to see the egg float or sink in different liquids. We put oil in the glass with salt water, and the egg floated where the oil and salt water met.
Sarah, age 11 of HI wrote:
The egg does float! I had to add a lot more salt... and I used different directions than you... but... It floats!
Gabe, age 13 of MB wrote:
it floated and it was amazing.
Stephanie of Bell Gardens, CA wrote:
It worked! it was totally awsome!!!