MIDDLE SCHOOL EXPERIMENT: Getting a Charge Out of Life!
Cumulonimbus clouds often build up a negative electrical charge at the base of the cloud and a positive electrical charge in the top of the cloud and are capable of generating lightning. The charges are carried by the water droplets or ice crystals located inside the cloud structure. You can see streaks of lightning because the air in the lightning discharge becomes ionized into what is referred to as plasma. Lightning causes hundreds of thousands of dollars of property damage and hundreds of deaths each year. Scientists also observed lightning on our sister planets Jupiter, Saturn, and Venus.
National Science Education Standards Addressed
- Abilities Necessary to DO SCIENTIFIC INQUIRY/UNDERSTANDING About SCIENTIFIC INQUIRY
- PROPERTIES and Changes of Properties in MATTER/TRANSFER of ENERGY/NATURAL HAZARDS
- Understanding About SCIENCE and TECHNOLOGY/Science and Technology in SOCIETY
- One 200 mm diameter styrofoam plate
- A piece of wool cloth
- A 200 mm diameter aluminum pie plate
- One 250 ml styrofoam cup
- One roll of masking tape
Carefully follow the directions in this experiment and you will make an amazing discovery. Select one member of your group to bring the materials to the table. Place the Styrofoam plate upside down on the table. Attach the Styrofoam cup to the middle of the upright aluminum pie plate with masking tape. Rub the Styrofoam pie plate with the piece of wool for one minute. Charge the aluminum pie plate by using the Styrofoam cup like a handle and placing it on top of the Styrofoam plate. Using only the Styrofoam cup, move the pie plate a few millimeters from the Styrofoam plate. Discharge the pie plate by touching it with an outstretched finger. Still using the Styrofoam cup as a handle, move the pie plate over to another group member. Have that group member touch the pie plate with one outstretched finger.
- As observers, how did your group members react as they touched the aluminum pie plate? Did anything happen the second time someone touched the plate? What happened each time and why?
- What did the group members hear, feel, see, or smell as the pie plate was being discharged? Why?
- Repeat the steps of the experiment up to the point where a group member touches the pan. Move your equipment to a darkened corner of the room. Discharge the pan by having a different group member touch the pan. Describe what happened and why it occurred. Why did the lowered light assist you in determining ion flow?
- How does this experiment relate to the study of lightening and static electricity? Give a minimum of five examples of static electricity we encounter in everyday life.
- With the help of the library or internet, design an experiment which will allow you to build a device that detects electrical charge. Repeat the experiment above using the device you built to detect the charge. What were the results of this experiment? Why?
- Use a computer to research the device on the internet. What is the formal name of the device you built? How is it commonly used?
- On the internet, find an experiment designed by Whelmer that deals with electrically charged pieces of lumber (2 x 4's). Conduct the experiment. What were the results of the experiment and why? What new piece of knowledge have you contributed to this field of research by conducting the experiment?
- Prepare to report your research findings to the public. In order to do so, you may choose to use any of the following strategies to prepare your report. Keep in mind you must emphasize research results and applications to real world situations. The strategies include make a photo montage, make a photographic journal, sketch a story board, write a song, write a poem, write a newspaper article, write and illustrate a TV News Brief, prepare a bulletin board, prepare a science fair display, prepare a TV or radio advertisement, prepare a newspaper advertisement, or design a new experiment of your own.