Why Do Metals Burn Different Colors?
When we observe the construction and steel companies, we can see some metals being melted and burned. At this point, there is light being emitted which produces different colors. Metals are made up of different elements so when these elements react with heat, light is emitted.
To understand this better, let’s take a look first at the properties of metals. These properties are malleability (can be shaped or bent); luster (becomes shiny when polished), and conductivity (conductor of heat and electricity).
Metals can be noble (unreactive), alkali (low melting point), alkaline earth (harder and higher melting point than alkali) , transition (hard, shiny, strong, and can be shaped), and poor (fairly soft and becomes useful only when combined to other substances).
Metals are also made up of atoms which has a nucleus. Around the nucleus are electrons orbiting near or far from the nucleus. If energy is applied to these atoms such as heat or electromagnetic radiation, some electrons will absorb the energy which may cause the atoms to travel to long distance more energetic shell. Then, these electrons will drop back to the lower shell. When this happens, a tiny particle of light can be observed. The color of the light may also differ in the energy level of the two shells where the electrons have fallen.
Electrons do not only fall in two shells. It can bounce back to different shells at different levels. When this happens, number of colors can be seen. Sometimes, a mixture of color can be seen which is also called as spectrum of light.
This is what happened when we watch fireworks. Fireworks produced different kinds of light because the metallic compounds are heated and exploded. Fireworks spark because of the energetic electrons in the atoms of the metals and compounds used metal powders. There are different colors to be seen because of the different metals present. Copper can produce blue-green color, potassium burns purple, and calcium may produce red color lights.