Transcript Optics: (The Act of Seeing)

Atoms and Electricity
All matter is made of atoms. Atoms are
made of protons, neutrons, and
electrons. Electrons orbit the nucleus
of an atom. Electrons can be added
and/or removed from an atom.
Electrons cannot occupy the same
space at the same time.
Atoms and Electricity
 therefore,
when electrons move from
one object to another it causes the
electrons in second object to move.
The rapid movement of electrons is
referred to as electricity.
Electricity
Electricity results from a flow of charges
that may be negative or positive.
 Material that allows electrons to flow are
called conductors (all metals are
conductors and some better than others)
 Material that does not allow electrons to
flow are called insulators (rubbers,paper,
and plastics are some examples)

Insulators and Conductors

Internal friction involves the restriction of
electrons from flowing in an object.

Insulators and conductors both have
internal friction associated with them.

However, conductors have significantly less
internal friction than do Insulators.
Types of Electricity

Static Electricity: A build up of charge on an
object (the electricity does not flow. It stays
stationary until transferred). Charging can
result from friction or contact.

Current Electricity: A process in which
electrons flow from one point to another
through a conductor
Current Electricity

Current Electricity results from charges (e- ‘s)
moving from one place to another through a
conductor.

Current electricity can travel through two basic
types of circuits (Parallel and Series)
Circuits: Series vs. Parallel
Series Circuit
Parallel
Series vs. Parallel Circuits

Name two things that are common between the two.
The basic parts (resistor, switch, potential difference
source (battery)

Name two things that are different b/t series and
parallel circuits. (They both have a different # of
electrical loops. They offer different amounts of
energy)
What would be the advantages and disadvantages of
using series or parallel circuits in a home.

Calculations



Resistance (R) the amount of internal friction in
a material that is measured in a unit called
Ohms (omega)
Current (I) the measure of the flow of electrons
that is measured in Amps (A).
Voltage (V) the measure of the potential
difference source (the push behind the
electrons) that is measured in Volts (V).
Calculations

Electrical Power (P) is the measure of how
much electrical current is required by appliance
to function.
Basic formulae and calculations

Resistance (R) = Voltage (V) / Current (I)

Power (P) = Current (I) x Voltage (V)

Power (P) = (Current)2 (Resistance)

What would these look like like in triangle form
?
Let’s Make Calculations

See textbook page 443 (1-4)

See textbook page 451 (1-5)

See textbook page 452 (1-8)

Use the GUESS method