Consider the following discussion between the two students about the atoms and light coming from the red "OPEN" sign from the previous question and the light coming from a yellow "OPEN" sign they see across the street. Student 1: I think that all you need to do to get signs to give off light of different colors is to use tinted glass of different colors. If you electrify a gas, white light is emitted so the color of the glass gives the sign its color. Student 2: That can't be it because the electrons will always move between the same energy levels for atoms in a neon sign and so they will only give off red light. I think the yellow sign is filled with a different type of atoms with energy levels that are farther apart so when the electrons move from one level to another the atoms give off yellow light instead of red light.

To understand this, let us remember that each chemical element has a particular atomic number. The atomic number determines the atomic radius of that element. In addition, the atomic number is also related to energy levels. This is because the atomic ray refers to the distance between the nucleus of the atom and its last electron, and the energy levels refer to the distribution of electrons.

In summary, the greater the atomic number, the greater the atomic radius and the greater the number of energy levels.

Understanding this, we will visualize any atom with a certain distribution of electrons at different levels of energy. These electrons can move from their energy level to another level if they are excited by an external energy, such as the energy that powers the traffic lights, for example. Upon receiving energy, the excited electron jumps from its energy level to more external levels.

when the electron moves from one energy level to another level, we can consider a case of energy conservation. This is because when jumping, the electron emits an energy of the same intensity that it received. This released energy is in the form of a photon. The emission of a photon allows the observation of a color, depending on the energy level of the electron.