Seventh Grade, Chemistry Science Projects (35 results)

You know that water can exist in three separate phases: solid (ice), liquid (water), and vapor (steam). To change from one phase to another, you simply add (or remove) heat. When water boils, what happens to molecules (for example sugar or salt) that are dissolved in the water? Do they boil off too, or do they stay behind? Read more

Some plastics undergo an unusual transition, from a hard, glassy state to a soft, rubbery state, with increased temperature. For this project, you should do background research on the effects of temperature on different types of plastics. Make sure that you understand the difference between thermosetting and thermoplastic polymers. You should also look for information on the glass transition temperature (Tg) for different plastics. Pure polyvinyl acetate has a Tg of 28 C (about… Read more

Fill a jar a little more than half full with fresh water. Make a solution of salt water, and add a drop or two of food coloring to it. Pour the salt water solution into a plastic cup with a small hole in the bottom, and then place the cup in the jar with fresh water. (The only connection between the fresh and salt water should be via the hole in the bottom of the cup.) With the right combination of hole size and salt concentration, you will see an oscillating current develop in the jar. … Read more

Many disposable diapers contain a polymer, called sodium acrylate, which is useful for absorbing water. Do background research to learn about sodium acrylate, and how it reacts with water. Make sure that you understand the terms hydrophilic, polarity, hydrogel and hydrogen bonding. Cut out the middle, padded section of a disposable diaper. Cut this into equally-sized square pieces, approximately 10-12 cm on a side. Remove some of the stuffing material so that you can staple the open… Read more

Have you or one of your pets ever been sprayed by a skunk? Hopefully not, but if you have, you probably know that the smell can be very unpleasant and hard to get rid of. There are many "folk remedies" for getting rid of skunk scent, but if you ever do get sprayed by a skunk, how will you know which one to try? In this science project, you will test the ability of various mixtures to remove the bad scent from rags that have been contaminated with bottled skunk scent, and determine which one… Read more