SWBAT: Describe static charges
and the different ways to gain a
static charge
Its Electric
Electric Charges
• There are two kinds of Electric Charges
– Positive charges posses more protons
– Negative charges posses more electrons
– Things that have no charge are said to be neutral
and must have the same amount of protons and
electrons.
• An electron has the same amount of negative
charge as a proton has positive charge
Charge Interaction
Charging an Object
• The only way to give an object a charge is
through the transfer of electrons.
• Protons are never transferred.
• For a positive charge electrons are taken away
• For a negative charge electrons are received.
• Insulators do not allow electrons to flow
• Conductors do allow electrons to flow
Charging by Friction
• When two objects are rubbed together
typically one of the objects will “steal”
electrons from the other.
• The electron “thief” becomes negatively
charged, while the “victim” becomes
positively charged.
• Examples:
– Balloon against shirt
– Feet against a carpet
Charging by Conduction
• Also called charging by contact
• Objects touch each other and electrons from
high concentration travel to lower
concentration of electrons.
Charging by Conduction
• What happens if a positive metal spoon
touches a neutral metal fork?
• A negatively charged metal sphere touched
another neutral metal sphere the same size,
when do the electrons stop flowing?
Charging by Conductions
• What if the charged sphere is touched to the
Earth? What is that called?
• Grounding: Touching a charged object to the
Earth (or a conductor touching the Earth) as a
means of eliminating its charge.
If you miss one of MR.
Miller’s classes you are
GROUNDED!!!
Charging by Induction
• No physical contact between two objects
• Inducing Conductors
– A charged object brought near a conductor will
force electrons to move along the conductor
• Examples:
– Soda can on a string