Jump to Instructions. Continue to Content. Materials water small toys Optional. To make it more fun, I made the ice cubes with ocean toys inside.
Make sure they are small enough to fit into the ice cube tray. Tools silicon ice cube tray adult supervision. Instructions Make ice cubes the night before the experiment You can put small toys inside the ice cube tray before filling it up with water.
Carefully put the tray into the freezer and wait for the ice cubes to form over night. Pop out the ice cubes. Place the ice cubes on a plate and sprinkle some salt on them. Put one end of the thread on the ice. Press it with your finger for a few seconds. Take away the finger and leave the ice unmoved for 2 minutes. Grabbing by the thread, slowly lift the ice cubes. If the thread is not sticking on the ice, try steps again but leave it untouched for a longer time.
While you wait for the ice cubes to form, create a chart where you can record the time minutes it takes for each ice cube sample to melt. Step 6 Remove each Dixie cup from the freezer and place outside in the sun. When one of the ice cubes melts completely, record the time under the correct column for that sample.
Keep the timer running and record the time it takes for each ice cube to fully melt. You may stop the stopwatch after the last ice cube melts. If you live by a beach, lake, or pond, try taking a water sample from some natural water bodies near you to compare in this experiment. This will help you observe more directly how the sun affects different bodies of water on our planet, depending on the type and amount of dissolved solutes they contain.
When the salty ice cube was placed in the sun, the lower freezing point combined with continuous heat from the sun made the ice melt much faster. When rainwater comes into contact with soil and rock material, some of that material dissolves in the water.
Because of this, many of the water bodies on Earth lakes, rivers, bays, lagoons, ponds, streams, oceans, etc. The ocean contains a high concentration of dissolved salts. The ocean begins to freeze when it reaches a temperature of When winter comes around the next year and temperatures reach Our planet is experiencing global climate change and an increase in global temperatures due to burning fossil fuels.
Scientists have proven that the amount of sea ice in the Arctic Ocean has been declining rapidly over the past few decades because of this warming trend. Experiment Overview: Ice forms when water freezes. Before beginning, think about the following questions and write down your predictions : Do you think all of the ice cubes will melt at the same time?
Do you think there will be a big difference between the ice block that melts the fastest and the ice block that melts the slowest? Experiment Materials:. Experiment Process:. Step 1 Measure one tablespoon of each substance and place in four separate Dixie cups.
In a solution there is a solute salt in this example that gets dissolved in a solvent water in this case. When other substances are mixed with water they may also lower its freezing point. In this science activity you'll investigate how salt, sand and sugar affect water's freezing point.
Observations and results Did the ice cube sprinkled with table salt melt the fastest? In this activity you tried adding salt, sugar or sand to ice to see whether the substance would help melt the ice.
In other words, you wanted to test whether these substances could demonstrate freezing point depression, or the lowering of the ice's freezing point so that it melted into a liquid at a lower temperature than normal. You should have seen that the ice cube with salt sprinkled on it melted faster than any of the other cubes.
This is because the amount by which the freezing point is lowered depends on the number of molecules dissolved, but not their chemical nature. This is an example of what's called a "colligative property. Cleanup Be sure not to pour the sand down a sink drain or garbage disposal! Instead, throw out the damp sand outside or in a trash can. This activity brought to you in partnership with Science Buddies.
Already a subscriber?
0コメント