Lightning Sparks
Purpose/Hypothesis
Lightning that is produced during a storm is simply a massive electric spark, which is called static electricity. Friction causes the particles to separate into positive and negative charges. These opposite charges attract one another, and when the electric charges are separated they look for a way to get back together. In a storm, the jump of numerous negative charges reaching out towards the positive charges produces a bolt of lighting. A miniature version of static electricity will produce sparks and an attraction between charged objects.
In this experiment you will explore what happens when you cause charges to separate. You will use friction to create electrical charges on a balloon, and observe how three different objects react to these charges. The three objects you will use are: salt and pepper, water, and another balloon.
Before you begin, make an educated guess about the outcome of this experiment based on your knowledge of lightning and charges. This educated guess, or prediction, is your hypothesis. A hypothesis should explain these things:
- the topic of the experiment
- the variable you will change
- the variable you will measure
- what you expect to happen
A hypothesis should be brief, specific, and measurable. It must be something you can test through further investigation. Your experiment will prove or disprove whether your hypothesis is correct. Here is one possible hypothesis for this experiment: "If enough charges are separated, the balloon will attract different objects and create electricity."
In this case, the variable you will change is the separation of the negative and positive charges on the balloon. The variable you will measure is how the balloon's charges are attracted to other objects.
Having a control experiment will help you isolate each variable and measure the changes in the dependent variable. Only one variable will change between the control and the experimental setup, and that is the amount of charged particles. At the end of the experiment you will compare the charged balloon with the neutrally charged balloon.
What Are the Variables?
Variables are anything that might affect the results of an experiment. Here are the main variables in this experiment:
- the object that is charged
- the degree of friction
- the material that produces the friction
- the distance from the balloon to the objects
In other words, the variables in this experiment are everything that might affect the charge of the balloon. If you change more than one variable at the same time, you will not be able to tell which variable had the most effect on the action of the charged particles.
Level of Difficulty
Easy.
Materials Needed
- two balloons
- salt and pepper
- access to sink
- small plate
- wool cloth or nylon (optional)
Approximate Budget
$2.
Timetable
30 minutes.
How to Experiment Safely
This project poses little hazards, but remember you are experimenting with electricity, however small. Do not conduct this experiment if there are any flammable vapors in the air, such as gasoline from an open container.
Step-by-Step Instructions
- Sprinkle some salt and pepper on a plate.
- Inflate both balloons. For the control, do not rub one balloon. Place the balloon about 1 inch (2.5 centimeters) above the salt and pepper. Then place the balloon about 1 inch (2.5 centimeters) away from a trickle of water from the faucet. Note the results.
- Rub the second balloon briskly against a piece of wool or your hair.
- Hold this balloon about 1 inch (2.5 centimeters) above the salt and paper. Note what you see and hear.
- Hold the balloon about 1 inch (2.5 centimeters) from a trickle of water. Note the results.
- Darken the room. Rub both balloons against a cloth or your hair, and place them together. Note what you see and hear.
- Place your hand gently over the section of the balloon that you rubbed. Again place the two balloons together and note the results.
Summary of Results
Create a data chart that describes the results of each trial. Compare the results to the control experiment. What did placing your hand over the balloon do to the charges in the balloon? Write a paragraph explaining your conclusions. Include how powerful bolts of lightning relate to this experiment.
Troubleshooter's Guide
Below is a problem that may arise during this experiment, a possible cause, and a way to remedy the problem.
Problem: There was no difference between the control and the experimental balloon.
Possible cause: You may not have created enough friction, in which case not enough charges would separate. Try rubbing the balloon vigorously against your hair, and repeat the experiment.
Change the Variables
You can change the variables in this experiment in several ways. You can use different types of material to create friction, and determine if this produces less or more attraction. You can also create charges on different objects, such as a comb. Try creating sparks or picking up different objects.