Around this time it is very common to find one of the things that fascinates both grown ups and children, fireworks. Today I would like to talk about them, specifically one of their characteristics that strikes us the most: the different colors they make in the sky.
Fireworks come from the east since its main element, the black powder, was invented in China centuries ago. Thanks to The Silk Road, pyrotechnics spread throughout the West, until it became a fundamental part of the traditions around most of the world, as it is today.
A rocket has two main components inside it, gunpowder and a specific mineral for each one.
The first generates the flame and power that will cause the rocket to rise and explode.
But the second does not contribute to the fire, nor does it allow it to burn more easily or rise higher. It only has one purpose: color.
Minerals are mainly composed of salts of different metals, such as Sodium, Copper, Barium or Strontium, when they come into contact with fire these metals cause the flame to be Yellow, Blue, Green or Red, respectively. When exploding at a great distance in the air, the fire generated by gunpowder is colored by these compounds.
This phenomenon is due to the minerals in the fire separating each of the elements into ions, and causes some atoms to have a very particular behavior. They absorb heat from the fire and expel light.
We could explain this by thinking of an individual atom and taking into consideration that when it comes to the electrons that surround it, they have specific places where they can be. Due to the heat, the electron that is furthest from the nucleus, passes to the next orbital, causing the atom to absorb energy in the form of heat. But as that electron in the new orbital is very unstable, it falls to its place of origin producing a photon of a given energy, in other words, generating light of a specific color.
As each atom is different, the fall of the electron changes, causing the color to vary among them, and thus causing the colors that are seen in the fireworks.
That is why, when the sky is dyed green, orange or red the last night of the year, it offers the electrons that make our life have many different shades, for the minerals that they put in the rockets and for all the scientists who make our lives much more interesting, and in this case, more colorful.
