Grade Level: 6th - 9th; Type: Physics
To determine what a plasma ball is and how it works.
- What is plasma?
- What are ions?
- What are inert gases?
- What is the Tesla coil and how is it used?
- What precautions should we take in working with the plasma ball?
- How is electricity generated and conducted in the plasma ball?
The student will acquire basic information on the phenomenon called plasma and the applications of this unique coil. First and foremost, plasma is created whenever atoms of a gas are heated up to very high temperatures. As a result the atoms have so much energy that when they collide, the electrons are thrown off. What plasma is is a group of electrons and ions. The plasma ball is an electrical apparatus invented by Nikola Tesla in 1894. In the 1980s it gained popularity. It is essentially a glass globe with a central electrode. The globe is filled with a mixture of inert gases. It works just like a teals coil and is useful in conducting electrical experiments. In fact, it can be viewed as a miniature Tesla coil. Inside the ball is a coil of wire that has a very high frequency passing through them. Translated, this means the electrons in the wires are oscillating very quickly. The result is that the atoms around the coil lose their electrons and plasma is formed. Because the globe has had some of its air removed (sucked out) it is very easy to makes electric sparks and readily sees them. In short, plasma is a partially ionized gas and therefore the ability of the negative charges to move about makes it very responsive to electromagnetic fields. Plasma, having these unique properties is considered to be the fourth state of matter.
This science fair experiment also serves to acquaint students with the essential processes of sciencing such as the importance of the use of a control, of identifying dependent and independent variables, of data collection, of pictorial and or graphic presentation of data and of being able to make better judgments as to the validity and reliability of their findings. They take on the role of scientists and in the process they learn to act as one.
- Plasma ball (available at toy stores)
- fluorescent light tube (available from local hardware store),
- a wooden stool or wooden chair (not metal)
- a few pennies and a multimeter (borrowed from the school`s physics lab).
- Gather all the materials you will need for this project. These include the plasma ball, the fluorescent light tube, the wooden chair or stool, some pennies and a multimeter borrowed from the school`s physics lab. Get someone to serve as a helper or partner
- Copy the Data Chart provided on the next page so that you can readily record your observations.
- Start by putting your hand on the plasma ball. Record what happened.
- Now put the fluorescent light tube close to the plasma ball. Record what happened.
- Get your partner to help with this. Stand on the chair and put your hand on the ball. Do not touch the ends of the fluorescent tube that you will now ask your partner to hand you. O.K. Now ask your partner to hand you the fluorescent tube. What happened? Record your observation.
- Get off the chair. Stand on the ground and repeat step 5. What happened? Record!
- Place a penny on the top of the plasma ball. Now, carefully, touch the penny with another penny. Don’t touch with your finger! You will get a shock!
- Now measure the electric potential around the ball by placing the first lead on the glass surface and moving the second lead around. Prepare to diagram the electrical field around the ball by taking measurement all around it. Finalize your diagram.
- Write up your report. Include all of your observations and your diagram. Be sure to include your bibliography as well as the basic information you obtained in your research. Did you enjoy doing this project? What did you like about it? Are there any father steps you would take to learn more about the plasma ball and plasma itself.
Chart of Observations
|What happened when:||Observations and Responses|
|#1 .Put my hand on the ball|
|#2. Placed fluorescent light tube close to the ball|
|#3. Was handed fluorescent tube while on chair|
|#4. Was handed fluorescent while on floor|
|#5. Place a penny on ball|
|#6.Touched penny to penny on ball|
Diagram: Label the Connections
- Does the electric field look like afield around a point charge?
- Can you find the equipotential lines?
- Using the measurement, can you calculate how much potential energy you need to lightup the fluorescent tube?
Terms/Concepts: Matter, states of matter, electrons, ions, inert gases, Tesla coil partial vacuum, conductor, capacitate, electric field, multimeter.
Eisenkraft,A. Active Physics, It`s About Time,Inc. Armonk, NY 1998