Static electricity

• Natuurkunde
• Middelbare school
• havo, vwo
• Leerjaar 2,3

static electricity

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You can explain the flow of electric current

You can explain what causes static electricity

You can explain why static electricity could be very dangerous

Rub your pen against your sweater.

Then try if you can pick up some paper snippets.

Rub a dry plastic comb through your hair for about ten times.

Of course your hair needs to be dry as well otherwise it would behave as a conductor

Then place the comb near a very narrow stream of water.

1

You can change some variables to experiment:

1. the temperature
2. a bigger comb
3. the material of the comb
4. the strength of the waterflow

2

SIMULATION

Static electricity

Static electricity is a build up of electric charge on insulated materials. This cause sparks when discharged.

Normally all materials are neutrally charged meaning that all positive and negative charges cancel each other out.

Because of friction this situation may change.

When two objects are rubbed together, the friction causes electrons from one object to move to another.

This causes one of the objects to become positive, while the other becomes negative. 

This only works with insulating materials since the electrons would flow right back if you use a conducting material.

As you can see in the picture the way the electrons move from one object to another depends ooon which type of materials are rubbed together!

!

And when you have changed the net charge in an object, 

you can use that very object to influence it surroundings

Because of the friction between two objects and the movement of the electrons, you will get a charge buildup eventually which can cause a potential difference.

This may result in an electric shock which could be very dangerous like on the case of fueling an airplane or lightning for instance.

Potential difference

Lightning?

It is very dangerous and deadly

Read this article 

and think about what if it was you.. what would you have done?

What can you do

to prevent this?

Building blocks

Materials are made out of tiny molecules and atoms. 

When you look deep down into an atom you will 

discover that it is made out of protons (+), neutrons

and electrons (-). 

Normally most substances are neutrally charged, 

meaning that you have an equal amount of positive

and negative charged particles.

Under certain circumstances the negative particles 

can move around causing a change in the overal charge.

nucleus

Conductivity

In some materials some of the electrons experience less 

attraction by the positive charge in the atom's nucleus.

Because of this, they have a chance to move around.

This can be caused by simply rubbing the material, but

also by connecting it in an electrical circuit.

From now on we call moving electrons electric current.

Although electrons (-)  flow towards a positive (+) charged 

objects, it is agreed upon that when we talk about 

electric current the current flows from + to -

Insulator

conductor

Electric current

Electric current is caused by the movement of electrons 

(electric charge) from one place to another. The electrons 

carry energy which they can give away where needed. 

After transferring their energy they will continue on their

way to the other side of the battery (or powersource). The

electrons themselves are not used. You can compare them

with a shopping cart which is returned after transferring 

your groceries to your car.