Experimentation of all kinds is part of everyday life. Experiments are also a very important part of science, and they can allow children of all ages to learn new things while having fun!

By using the scientific method and by doing experiments we promote children’s reasoning skills, we fuel their curiosity and their desire to learn.

Here is an experiment that demonstrates the effectiveness of soap, and the importance of washing hands to prevent germs!

Step 1 : Getting ready

Here is what you will need : 

  • Ground Pepper 
  • A plate filled with water
  • Dish soap  

Etape 2 : Here we go!

Pour water on the plate and add a little pepper to the water. Then dip your finger in the dish soap and dip your finger in the middle of the plate. The pepper immediately runs away as far as possible from your finger!


This experiment can be compared to the effect of soap on germs to show the importance of washing your hands often to fight bacteria and viruses. The virus, here represented by pepper, runs away when approaching soap, and you are thus protected!

Here is a more detailed scientific explanation for your older children. Water has a surface tension that keeps the water molecules bonded together and this forms a kind of membrane. When you put your finger covered with dish soap in the water, the surface tension is broken because of the dish soap because it is surfactant, which means that it decreases the surface tension (the water molecules’ attract less).

Therefore, when the detergent encounters the water, the surface tension is lower, and this effect is propagated. The pepper is then pushed out of the plate at once! It is a physical, not a chemical phenomenon.


In today’s diary, kids can document the day’s activity. For example, by drawing the experiment, or by inventing a story with it, or by finding other explanations for phenomena which may seem magical!

Here are a few questions that might fuel a discussion surrounding this activity :

  • What was most impressive with this experiment?  
  • Did it demonstrate the importance of washing your hands often?
  • Can you think of other experiments that we can do at home?  

Did you know...

  • … To carry out a scientific experiment, researchers have a certain approach to follow: this is called the scientific method. It’s a bit like a cooking recipe, with different stages. To find out more click Here 
  • … Science is used to understand and explain the world around you. Check this video out
  • … Over time, scientists have found rational explanations for many phenomena that were considered magical because they were not understood. Even today, we discover new things every day! For example, we now have a better understanding of the weather phenomena and we can even predict it!

Furthermore, here are three other easy scientific experiments that can be done at home!


Activity by Ari Bouclette