Electricity demo 1 Flashcards
Static
Build up of electrons in insulators
Current
Flow of electrons in conductors
Electricity and the Atom
Electricity is the result of the movement of electrons, which are far from the nucleus of the atom.
Protons don’t move
conductor
Substances with electrons that move easily are called Conductors.
insulators
Substances with electrons that can’t move easily are called Insulators.
conductors + insulators
Both substances can be charged if electrons are gained or lost.
neutral charge
Objects with an equal number of protons and electrons have no/a neutral charge.
negative charge
An object that gains electrons gets a negative charge.
postive charge
An object that loses electrons gets a positive charge.
3 LAWS OF ELECTROSTATISTICS
- Like charges repel
- Unlike charges attract
- Charged objects attract neutral objects
Neutral Objects Attracted to Charged Objects
Charged objects will attract a charge on a neutral object. The opposite charge is always close to the charged object, so there is attraction.
Protons still don’t move, the electrons just move closer.
Metal Leaf Electroscope
A device that can be used to determine an electric charge is called a Metal Leaf Electroscope
You can see if an object is charged when the leaves repel.
3 Ways to Charge an Object
Friction: Contact (opposite charges)
Conduction: Contact (same charges)
Induction: No contact (opposite chargers)
Friction
Rubbing two insulators together
One object has a strong hold of electrons (negative charge)
One object has a weak hold of electrons (positive charge)
After charging has opposite charges
Conduction/Contact
When a charged object touches a metal object, electrons move from more electrons to less electrons.
When a negatively charged rod touches a neutral object, the electrons flow from the rod into the object.
When the rod is removed, the object now has a permanent negative charge.
Induction
No contact—A static charge can be produced without contact with a charged object. This process is called induction and works because a positive or negative electric charge can attract or repel electrons at a distance.
temporary
A negatively charged object comes near a neutral object, the electrons in the neutral object move away. Therefore, the side near the charged object appears to be positive.
A positively charged object will attract electrons in any object it comes close to. The side of the object closest to the positive object will have a temporary negative charge since the electrons will move toward it.
Permanent
If you are charging by induction and the object is grounded, the object can become permanently charged. Just remove the ground before the charged object is removed. You will always end up with the opposite charge from the object used to induce the charge.
