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Science Rocks!

What's More Dense?


your results

Sent in by:
Paul of Eagan, MN

More dense experimentation!

Materials Needed

  • one cup of water
  • one cup of light corn syrup
  • one cup of cooking oil (like vegetable oil or corn oil)
  • food coloring (to be added to water)
  • nickel
  • grapes
  • Lego(tm) piece
  • one large clear container, like a pitcher



  1. Do you think a grape will sink or float in syrup? How about in water, or in oil?
  2. First, add some food coloring in the water. This will help you see the water. Then, drop one grape into the cup of water, one grape into the cup of corn syrup, and one grape into the cup of cooking oil. In which liquid does the grape float and in which does it sink?
  3. Next, try dropping a Lego(tm) piece and a nickel. Will they float on the syrup, will they float on the water, or will they float on the oil? Or will they just sink?
  4. Then, combine the cups of syrup, water and oil into the large clear container. What happens?
  5. Density is one of the things that makes things float. The three liquids float on top of one another because they have different densities. The syrup is the densest. The oil is the least dense. The water's density is in between the syrup and oil.
  6. All three liquids take up the same amount of space in the container. But the denser one, the syrup, is heavier. That's why the water floats on the syrup. The oil is less heavy than the water. That's why the oil floats on the water.

Keep experimenting with these three liquids and then send any other discoveries you make to the ZOOMsci feedback area.

Some of your Results

Abbey, age 10 of Southall, UK wrote:
The oil was at the top and I added food coloring. I then added salt and it was a lava lamp! Wicked! Thanks PBS!

Melody, age 12 of Auckland wrote:
This experiment was so cool! The water with the most salt was at the bottom and then came the water with some salt and last came the water with no salt. This experiment was very excited!

Mckenzie, age 12 of Auckland, NZ wrote:
I did it right straight away and it looked really cool, it was really coulourful, but the colours ran together a little bit. It was really cool!

Oliva, age 12 of Kalamazoo, MI wrote:
Saltwater is more dense than freshwater and eggs and eggs do not float in water because eggs are denser than water. If the object is denser than the liguid it's in it won't float.

Cookie, age 14 of Columbia, SC wrote:
I have a question, what about milk? Is milk more denser than water or syrup or oil? I think it is the same density as water cuz they mix when you pour them 2gether.

Brittany, age 15 of Delta, BC wrote:
I am a summer tutor and we are going to do this experament next week. I wanted to expand on this idea more so I started playing around with some other liquids and here is what I found: oil floats on vinegar, milk floats on honey, oil floats on lemon juice, maple syrup (pancake syrup) floats on corn syrup. That's all I have found so far, thanks for posting this!

Kevin & Ronaldo of Perth Amboy wrote:
The alcohol was less dense than the soap and alcohol and gel

Guy of Kansas City wrote:
Rasins, rice, and macorone were floating

Jonathan, age 10 of Perth Amboy, NJ wrote:
The rasin's, rice, and the macaroni was floating.

Marixa, age 11 of TX wrote:
I notes that the grape was more denser than all the odjects

Mackenzie of Menomonee Falls, WI wrote:
The cooking oil floated on top then the water, and then the corn syrup.

Jonna, age 9 of Chicago, IL wrote:
i found out that the grape was more dense and that oil is denser than water. I thank you guys bye.!!

Pedro, age 10 of New York, NY wrote:
the grape floated on the syrup

Kelaysia, age 11 of Clarksdale, MS wrote:
The 2 legos floated

Joyce, age 10 of Duluth, MN wrote:
I found that oil is denser than water.

Lorena, age 11 of Toppenish, WA wrote:
I filled a tub with water then I threw in a regular Pepsi then a Diet Pepsi. The Diet Pepsi floated and the regular Pepsi sunk because it had a greater amount of sugar. pretty wicked experiment!

Faith, age 12 of New York wrote:
it worked. the grape floated on the syrup. the nickel didnt float on the syrup because of its presure. the water floated on the syrup and the oil floated on the water

Angel, age 12 of Denver, CO wrote:
the grape had the most density

Patricia, age 10 of Chicago, IL wrote:
the grape did not float only in oil the toothpick floated th eraser sinked

Ana, age 10 of New York, NY wrote:
It worked just like when you did it! It was amazingly awesome! so cool!

Taylor, age 13 of St. Johns, NF wrote:
The same thing happened expect I used a penny and it floated on top of the corn syrup! And after I tried putting milk in it and it turns out that it has less density than corn syrup but more density than the oil and it made like milk bubbles formed with oil, water and milk! it was pretty cool!!!

Aditya, age 8 of Toronto, ON wrote:
The grape stayed longer compare to the popcorn seed, and the whole rasin was the same as the rasin.

Jacob, age 6 of Montreal, QC wrote:
We put water, oil, corn syrup and liquid hand soap together in a glass. The oil floated on the water, the water floated on the liquid hand soap, and the liquid hand soap floated on the corn syrup. The salt floated on the oil, except for some globs of salt that sank to the bottom of the glass. The ice cube floated on the oil until it started melting then it sank to the water level and floated on the water. The Lego and the grape floated on the water (between the oil and water). The nickel sank to the bottom of the glass.

Chelsea, age 14 of Columbus, GA wrote:
The molasis went to the bottom.

Tate, age 11 of Baudette, MN wrote:
The same result that was supposed to. Syrup is most dense.

Kemar, age 6 of Hollywood, FL wrote:
The apple juice stayed at the top and the vegeatale oil stayed at the top juice stayed at the very botom.

Kyle, age 10 of Kennetcook, NS wrote:
The water floated on the corn syrup then the oil floated on the water. I put ketchup in it and it all came apart.

Kayelan, age 12 of Gallatin, TN wrote:
I loved the project. I did it at home since I'm homeschooled. I used light corn syrup, vegetable oil, and water. The funny thing was, I didn't have any blue food coloring! So I used purple! I love purple. And everything worked great, but when I dropped the grape in, I couldn't at all! But I looked on the top and saw the grape. I blend in the purple water.

Kajamil, age 7 of Lancaster, PA wrote:
My object floated in the cooking oil and in the water, and in the corn syrup. It floated because it had air in it. It also weighs less than the cooking oil, water, and the syrup. That's how.

not yet implemented