Electricity
Electricity
• Electricity: A fundamental form of energy resulting
from the presence or movement of electrons
• Electric charge: A property of subatomic particles.
Electrons have negative charge and protons have
positive charges
• In an object only negative charges (electrons) are
allowed to move around.
Static Electricity
• Static electricity: the accumulation of excess charges
on an object by adding or removing electrons.
• Conservation of charge: When an object becomes
charged, charges are neither created nor destroyed.
They are only moved from one object to another.
• Transferring electric charges:
Conduction: Charging by contact
Induction: Rearrangement of charges on neutral
objects caused by a nearby charged object.
Voltage and Current
• Voltage: A potential difference between areas of
high and low charges. Charges will move from areas
of high voltage to areas of low voltage.
• Electric current: the movement of electric charges.
It is measured in Amperes. An Amp measures the
amount of charge that moves per second.
Conductors
• Conductors: A material that easily allows the flow of
electrical charges. These materials have loosely held
valence electrons.
• Examples: metals (copper, silver, gold, aluminum,
platinum, bronze, tin, zinc, etc.)
• These materials have low resistance to electrical
current.
Insulators
• Insulators: Materials that resist the flow of electric
currents. These materials have tightly bonded
valence electrons.
• Examples: rubber, plastics, wood, teflon, PVC pipes,
glass, clay, etc.
• These materials have high resistance to electrical
current.
Resistance at molecular level.
• http://www.micro.magnet.fsu.edu/electroma
g/java/filamentresistance/index.html
Electric Pickle!
Is a pickle a conductor or an insulator?
What might happen if we pass electric current
through it?