Science unit 2 Flashcards
What is a neutral charge
object has equal number of protons and electrons (0)
What is a positive charge
objet has more protons than electrons (+)
What is a negative charge
object has more electrons than protons (-)
What is static electricity
created when objects are rubbed together using friction
What is electric force
the force a charged object exerts on a near by object
what are the four laws of electric charges
- like charges REPEL
- opposite charges ATTRACT
- charged and neutral objects ATTRAT
- neutral and neutral objects have NO REACTION
What is an electroscope
device that detects the presence of an electric charge
What are the two types of electroscope
Pith Ball Electroscope & Metal Leaf Electroscope
What is a pith ball electroscope
-to determine if an object has a charge:
-bring object close to neutral pithball
-If object is neutral-pithball won’t move
-If object is charged- pithball will move
What is a Metal-Leaf electroscope
-to determine if an object has a charge:
-bring object close to metal ball
-If object is neutral-metal leaf will hang straight down
-If object is charged- metal leafs spread apart
-when you move the object away the leafs will return straight down
What are the three methods to charge objects
- Friction
- Conduction
- Induction
Rubbing two neutral objects together will result in:
a transfer of electrons. one object will become negatively charged and the other will become positively charged.
What is the electroscope series
(trio electric series)
-The electroscope series is a list of materials in order of increasing tendency to gain electrons.
-the higher material will LOSE their electrons and become POSITIVE
-The lower material will GAIN electrons and become negative
What are conductors
a substance that allows electrons to pass through them
What are insulators
a substance that does not allow electrons to flow freely through them
What are the two types of induction
1.temporarily charged buy induction
2.Permanently charged by induction
Charging temporarily by induction
(one object charged, one object neutral)
-When a charged object is brought NEAR a neutral object, it INDUCES the electrons to shift
-This results in an uneven distribution of charge, but this will only be temporary because the election will move back to their OG position
Charging by induction always results in 2 objects with oposite charges
- the original object that induces the charge keeps its original charge
- the other object which was induced receives the opposite charge
How to charge by conduction
-Need two objects
-objects must touch
-starting point: at least one (or both) objects must be charged
-End point: Both will end up having the same charge
-How? by moving ELECTRONS(never protons)
What is grounding
connecting an object to a big thing (like the earth) to remove an electric charge from an object
Lightning
- Tiny water droplets in clouds move around and they become charged
- all negatively charged water molecules collect at the bottom of the cloud
- the negative charges at the bottom of the cloud repel negative charges on the earths surface
- the ground temporarily becomes induced positively charged. This creates a charged imbalance
- If the imbalance is big enough, the positive and negative attract, and excess electrons from the cloud will move to the ground
- this causes the air to be superheated, which causes a flash of light and rumbling sound of thunder
