Why does salt turn a blue flame into orange?
This is due to the presence of sodium atoms in the salt (i.e. sodium chloride). The electrons orbiting a sodium atom can only occupy certain discrete energy levels. When they gain energy, for example when heated, they are excited and jump up to a higher energy level. However, the lower energy state is more favourable, and so the electrons lose this extra energy and drop back down. The energy is released in the form of photons (light), with the frequency (colour) of the light determined by the amount of energy. As the electrons can only occupy certain energy levels, only certain frequencies are produced, depending on the type of atom. In sodium’s case, it is orange.
