Let’s mix together some salt and pepper and then use science to separate them!
Separate Salt and Pepper Science Experiment Video
- Empty Dish
- 2 Tablespoons of Table Salt
- 1 Teaspoon of Black Pepper
- Plastic Comb
Step 1 – Place 2 tablespoons of salt onto an empty plate.
Step 2 – Add 1 teaspoon of pepper to the salt and gently shake the plate to combine the salt and pepper.
Step 3 – Take a clean plastic comb and run it through your hair a few times. Then position the comb above the salt and pepper and watch what happens.
How Does the Experiment Work?
Most objects do not have a positive or negative charge, they are neutral. Some objects, like hair combs, have the ability to become charged. At the beginning of the experiment, the comb has a neutral charge. When you run the comb through your hair, you give it an electrical charge. Running the comb through your hair allows electrons from your hair to move onto the comb. This gaining of electrons gives the comb an overall negative charge.
The pepper jumps to the comb for two reasons. The first reason is that grains of pepper are much lighter than grains of salt. If any salt does jump up to the comb, it will likely just fall back because it is too heavy. The second reason that pepper jumps to the comb is because of the idea that unlike electric charges attract. Remember the comb is negatively charged, so this negative charge attracts the positive charge in the grains of pepper. How does the pepper get a positive charge? Pepper polarizes easily, meaning the electrons move to one end of the pepper grain and the protons move to the other end. This leaves one end of the pepper grain with a negative charge and the other end with a positive charge. Salt does not polarize nearly as quickly as pepper.
The outcome of this experiment is a result of static electricity. Static electricity is a stationary (not moving) electric charge that is caused by friction. Lighting in the sky is a result of static electricity!
Other Ideas to Try
Try this experiment with other spices from your spice drawer! Try sugar, yeast, gelatin, garlic powder, garlic salt, lemon pepper seasoning, etc. and see what else is attracted to the negatively charged comb.
More Science Fun
Try your hand at these other experiments that involve static electricity:
I hope you enjoyed the experiment. Here are some printable instructions: