The BT Young Scientist – Ms. Mulcahy’s 4th Class

Ms. Mulcahy’s 4th Class worked hard over the past couple of months preparing for the BT Young Scientist. We, in 4th class, are extremely aware of the environmental issues in the world at the moment so our aim was to explore different energy forms.

We decided to explore electricity. We looked at all different forms of energy. While looking at different forms of energy, we discussed the importance of renewable energy.

After that we learned about the history of electricity, we learnt about two important people: Thomas Edison and Nikola Tesla. Thomas Edison invented the direct current. This is a current where electrons can only flow in one direction. He made the first light bulb. Nikola Tesla made the alternating current. The electrons in an alternating current can flow in both directions. They can also flow over long distances. We learned that we could find direct current in batteries and we can find alternating current in our mains electricity.

When we were first learning about electricity, we had to know what an atom was. An atom is the smallest particle of anything. It is made up three things, protons, neutrons and electrons. A protons is positively charged. A neutron has no charge and an electron has a negative charge. In order for electrons to flow we must have a complete circuit and good conductors. We decided we would use T-shirts in our presentation in order to show the movement of a free electron if you have a complete circuit. If the material is an insulator the free electron will not be able to move. For a complete circuit you need no gaps, power source and wires connected to the positive and negative ends of a battery. The positive end of a battery loves electrons so pulls them into the battery. The voltage of the battery is the pushing force to push the electrons through the battery and the negative side hates the electrons so it pushes the electrons away and encourages them to go back to the positive side making a complete circuit. We cool electricity quizzes to show what a complete circuit looked like.

Children will make electricity quizzes. Children will then conduct an experiment to see if fruit (renewable energy) is a good battery source. Children will decide which the best battery source is out of different fruits.

The trigger for our experiment: When we were making circuits Maya and Lidia had a problem. Their bulb would not light. Their battery had ran out of voltage. We wondered if there any renewable electricity sources we could use instead. So we decided to use fruit.

We had a starter questions: Can you power an LED light bulb with one piece of fruit?

We tested four types of fruit. Lemon, lime, potato and apple. None of these worked. We knew to make a battery we needed two electrodes and one electrolyte. We rolled the fruit to make the electrolyte – this was the citric acid. Our electrodes were copper (cathode) and zinc which was the anode. We tested the fruit to see if they created any voltage.

The answer was yes. So we knew that in order to power the LED bulb we would need to use more than one of the fruit. We used 7 lemons to power the LED bulb.  

After all this we decided we would like to bring our experiment to The BT Young Scientist and Technology Exhibition. It is an Irish annual school students’ science competition that has been held in the Royal Dublin Society, Dublin, Ireland. We had a fantastic day presenting to the judges and came away with a plaque and a certificate of participation!

As well as the student projects on display, there are a further four exhibition halls filled with science and technology based exhibits and entertainment. During the time when we were not presenting we were allowed to go around and see some of the other projects and interesting stands! It was a great day!

Post Author: Kimberly Mulcahy