Static Electricity: Charged!


BACKGROUND

What does lightning, the shock you get when touching something in dry weather, or the way clothing sometimes clings have in common?  It all boils down to some of the smallest particles of matter. All things are made up of atoms -- the smallest unit of matter that still has the properties of the corresponding element (such as gold, potassium, oxygen, etc). But, atoms are made up of even smaller parts: protons (positive charge), electrons (negative charge), and neutrons (neutral with no charge). The atom is kind of like a mini-solar system with the protons and neutrons together as a "sun" and the electrons orbiting around like the "planets". (This is a simplified picture, but sufficient here.) The atom as a whole is neutral in charge unless something changes its natural state. The electrons with their negative charge are relatively easy to remove. When this happens, the remaining atom (an "ion") has a positive charge and the electrons can move to other atoms giving them an excess of negative charge. When two materials with like charges come close together, they are repulsed, pushing them apart. On the other hand, when matter with unlike charges come close together, they are attracted to each other. Or, when a charged material comes close to a neutral one, the charges within the neutral atoms become unevenly distributed, the like charges moving away. On a larger scale, charges can accumulate in areas and build up. In the case of a static shock or lightning (an extreme example), the difference between an area of positive charge and negative charge is suddenly equalized by the flow of charges (called an electrostatic discharge). All these phenomena are a result of an imbalance of electrical charge. This is static electricity.

In our investigations below, static charge is produced by rubbing two materials together. As a result, one will lose electrons and one gain electrons. Which one gains and which one loses is dependent on the specific material. Rubbing a balloon with a cloth transfers electrons from the cloth to the balloon so that the balloon becomes more negatively charged. The build up of static charge doesn't last forever, though. With time, the excess negative charges dissipate. Furthermore, certain conditions affect how much static charge is produced. For example, fabric sheets are treated with material that when put into a dryer reduces the amount of "static cling". Let’s now apply this information to the results of the following investigation>

INVESTIGATION      

PLACE TO BEGIN:
How can you explore static electricity?  What kind of materials will respond to changes in the charge of other materials?  

MATERIALS:
Woolen cloth, plastic ruler, index card squares, samples of light-weight materials such as flour, sand, sawdust, puffed cereal, tissue paper bits, tiny leaves, pieces of thread


DIRECTIONS: Place small amounts of the various materials being tested on squares of index cards.  To text each material, wrap the woolen cloth around the plastic ruler and rub vigorously about 20 times.  Then take the ruler and hold it over a sample of material, one at a time and observe what happens.  Before testing the next material, remove anything clinging to the ruler and re-rub it with the woolen cloth.  How do the different materials compare in their response to the “charged” ruler?
QUESTION:  Knowing that rubbing an object with the cloth removes electrons from the cloth and that (1) like charges attract and (2) unlike charges repel, what can you infor about the charges of the materials?

GOING FURTHER:
(1) Test other materials placed on the cards.  
(2) Test other materials to rub the ruler (e.g. cotton, silk, polyester, nylon etc.).  
(3) Test to see how long a charge will last.  Place a series of cards with the same material (e.g. all puffed cereal) and don’t re-rub the ruler and find out if there is a lessening of the charge.  
(4) Use objects of other materials than plastic to be rubbed (e.g. wood, glass, rubber).  
Remember to keep everything else the same when testing something new (control the experiment).  Review the Scienticific Method

DEVOTIONAL   

Read John 12:27-36.  Jesus said that he would be lifted up, meaning that He was soon to be lifted up on the cross and die for the sins of all people — and ultimately would be lifted up to be seated at the right hand of God.  Jesus died for all no matter what a person’s age, race, sex or place of birth.  What remains is the question of whether one will accept God’s free gift of salvation.  

APPLICATION QUESTIONS: 
1. What was your response when you first heard that Jesus had died for you?  Were you drawn to Him and desired to know more?
2. Have you accepted Jesus as your own personal Savior and Lord?
3. Who can you tell about what Jesus did for all people who accept Him?


CREATIVE ACTIVITY

Make “electrostatic dancers”.  Draw a couple of people (dancer) shapes onto tissue paper and cut them out.  Tie a piece of thread to each dancer at their head and hang them a few inches apart on a plastic drinking straw.  Charge another plastic straw by rubbing it with your woolen cloth.  Rub the charged straws on the dancers.  To make them “dance”, move the charged straw near and around the dancers.



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