What extinguishes candles is the invisible gas that falls onto the flame. This gas displaces the oxygen that the candle needs to stay lit, because it is denser than the atmosphere and falls until it reaches the bottom of the glass. Indeed, the combustion of the candle is a chemical reaction. For this to occur, wax, oxygen and heat are needed. If one of these elements is missing, there is no combustion. Density has been important in experiments, such as when carbon dioxide sank to the bottom of the glass because it is denser than oxygen.
We have learnt that the Earth's interior is like a bipolar magnet and therefore generates a magnetic field. We have also learnt how to make an electrical circuit with a battery, an electrical cable and a light bulb, and we have verified that some materials are conductors of electricity. for example: metal Finally, we did the last experiment and found out why the compass goes crazy when we set up the electrical circuit and attract it with a magnet. The needle moves because of the presence of an electric current or a magnet near it. The electric current flowing through a coiled wire has the same effect as a magnet.