Embedded Files
Why does each tube emit a different colored light?
Introduction
Geissler tubes is the generic name given to glass tubes which have been evacuated and have two or more electrodes passing through the walls. For my project, I used two different types of tubes: tubes set at different pressures and tubes with different types of gasses. When adding a high voltage of electricity with the Tesla coil, each tube will start to glow or emit a colored light. Since each tube has a different property, be it a different gas or set at a different pressure, the tube will emit a different color.
Materials
Table or other flat surface
Tesla Coil
Geissler Tubes
one set filled with regular air but at different pressures: 40 mmHg, 10 mmHg, 3 mmHg, 1 mmHg, 0.1 mmHg, and 0.02 mmHg
set of different tubes filled with different gasses: Hydrogen, Neon, Carbon Dioxide, Argon
Procedure
Foremost, adult supervision is highly recommended because of high voltage energy produced by the Tesla coil. When setting up the Geissler tubes filled with air, it is important to order them from highest to lowest pressure. By doing this we will be able to distinguish the change in color. The other tubes with different gasses should be flat on a table.
You will add the electricity (voltage) with the tesla coil. Be very careful! Because of its high voltage, the electric current can jump and shock you! Repeat for each tube and observe the light being emitted.
Scientific Principle
As the electricity is applied to the discharge tubes, the electrons in the tube ionize which in turn emit a colored glow. In the first set of Geissler tubes, the ones filled with regular air set at different pressures, the electricity glows brighter at different pressures as well. This also has to do with the distance the electrons are from each other making either easier or harder to ionize.
Safety Regulations:
The Tesla coil is a device that exerts high voltages of energy. It is highly recommended to do this project under adult supervision. The Geissler Tubes are also very sensitive. Please handle with care.
Investigation Part
Why does each tube emit a different colored light?
Each tube has a different property than the last, be it a change in pressure or a completely different gas. Because of these changes, each tube will show off a different color.
Why do the tubes emit light when a high voltage is applied?
The metal plates at each end (cathode-anode) allows the electricity to travel from one end to the other. As the electricity passes through the gas, it ionizes the electrons and the gas emits a colored light.
What color belongs to which gas?
Hydrogen is a baby blue; Neon is a bright red-orange; Carbon Dioxide is a purple; Argon is a brighter purple
Why is Neon the brightest?
On the periodic table, ionization levels increase as you go left to right. Neon has one of the highest ionization energy levels, so it is able to emit a brighter light.
Page updated
Google Sites
Report abuse