Grade 11 have been learning about the structure of atoms, including the effects of electron excitation. The colours in the image are produced as a result of electrons in metal ions becoming “excited” after taking on energy through a process called “absorption”. When the electrons lose energy again, they emit characteristic wavelengths of light and we can identify metals by the spectrum that they emit. This experiment demonstrates the idea of quantum changes in the arrangement of electrons, which is a really important clue to how atoms work. These metals used are often found in fireworks to give them their characteristic colours.