Transcript Sta

Do NOW (on p 34):
Discuss with your elbow buddy Does this happen to you?
does your hair stand up when you take off your hat?
do you sometimes get a shock when you touch a friend?
Why does that happen?
Do now: energy
Static energy
What is Static Electricity?
Everything we see is made up of tiny little parts called atoms.
The atoms are made of even smaller parts. These are called
protons, electrons and neutrons. They are very different from
each other in many ways. One way they are different is their
"charge." Protons have a positive (+) charge. Electrons have
a negative (-) charge. Neutrons have no charge. Usually,
atoms have the same number of electrons and protons. Then
the atom has no charge, it is "neutral." But if you rub things
together, electrons can move from one atom to another.
Some atoms get extra electrons. They have a negative charge.
Other atoms lose electrons. They have a positive charge.
When charges are separated like this, it is called static
electricity.
 If two things have different charges, they attract, or pull
towards each other. If two things have the same charge, they
repel, or push away from each other.
 So, why does your hair stand up after you take your hat off?
When you pull your hat off, it rubs against your hair.
Electrons move from your hair to the hat. Now each of the
hairs has the same positive charge. Things with the same
charge repel each other. So the hairs try to move away from
each other. The farthest they can get is to stand up and away
from all the other hairs.
If you walk across a carpet, electrons move from the rug to
you. Now you have extra electrons. Touch a door knob and
ZAP! The electrons move from you to the knob.You get a
shock.
Do NOW: write on p 32-33
In A a charged rod is repelling a copper ball.
In B two charged balls are attracted.
A.
B.
+
?
+
?
1
?
2
Click in A =True; B= false
____ 1. In A the rod is positively charged
____ 2. In B, ball 1 has a negative charge
____ 3. In B, the positive charged rod will be attracted to Ball 1
review p 27-29
Static lightbulb
Static electricity
Static electricity is a
buildup of charge on an
object.
Static Electricity
 Like charges repel – unlike charges attract
 Positive (+) and Negative (-) charges attract
or pull together.
 Positive (+) and Positive (+) charges repel
or push apart.
 Negative (-) and Negative (-) charges repel
or push apart.
Van de Graaff Generator:
 When the motor is turned on, the lower roller (charger)
begins turning the belt. Since the belt is made of rubber and
the lower roller is covered in silicon tape, the lower roller
begins to build a negative charge and the belt builds a positive
charge.You can understand why this charge imbalance occurs
by looking at the triboelectric series: Silicon is more negative
than rubber; therefore, the lower roller is capturing electrons
from the belt as it passes over the roller.
http://amasci.com/emotor/vdgde
mo.html
Some atoms hold on to their electrons more tightly than others
do. Positive items in the series are at the top, and negative items
are at the bottom:
 Human hands (usually too moist, though) Very positive
 Rabbit Fur
 Glass
 Human hair
 Nylon
 Wool
Some atoms hold on to their electrons more tightly than others do.
Positive items in the series are at the top, and negative items are at
the bottom: from more positive to less positive
 Human hands







 Silk
(usually too moist, 
though) Very

positive

Rabbit Fur

Glass

Human hair

Nylon

Wool

Fur

Lead
Aluminum
Paper
Cotton
Steel Neutral
Wood
Amber
Hard rubber
Nickel, Copper
Brass, Silver
 Gold, Platinum
.
 Polyester
 Styrene







(Styrofoam)
Saran Wrap
Polyurethane
Polyethylene (like
Scotch Tape)
Polypropylene
Vinyl (PVC)
Silicon
Teflon Very negative
Exit ticket
 On p. 29:How did the
demonstration of the VDG
generator help you understand
static electricity and the way
charge transfers? Give 2 details
from your reading and the demo.
 Why did Morel’s hair go up?
Explain what happened.
 Use some of the terms: electrons,
charge, positive, negative, neutral,
like, unlike, attract, repel
 Continue on p 33.
Do Now:
What part of the magnet attracts
the most paper clips?
1. With your elbow buddy, use the bar magnet OR the
horseshoe magnet. Take turns with others at your table.
2. See if you can make a paper clip stick to different parts of
each magnet.
3. Draw a diagram on p 30 of your energy packet showing
the number and location of paper clips on each magnet.
Magnetism
 Magnets have 2 poles, North and South
 Opposite poles (North and South) attract
 Like poles (South and South) (North and North)
repel
 The area around a magnet where the force is
strongest is called the magnetic field.
Reflection:
 Look back at the activity at each station and reflect on
what each station showed you about magnetic force, or
the magnetic field.
 On the inside cover of your magnetic notebook, write at
least 1 sentence about what each station showed about
magnetism.You may want to use diagrams.
Terms to use: attract, repel, poles, force, magnetic
field lines
Crazy Scientists
 https://www.facebook.com/LiveOnlineRadio/videos/1015
6088161375075/
Do Now: with your elbow buddy
Using two wires, one battery and
a bulb, can you get the bulb to
light up?
Draw it in your Energy 2 packet
p 2.
Electricity
• Electricity is a flow of electrons
•An electric circuit is a pathway
that allows the flow of electrons.
•An electric circuit has 3 parts:
1. Power/Energy source
__ 2. Pathway
3. Resistor - Objects that require an
electrical current to work (ex. light bulbs,
fan, bell).
Do Now:
Using three wires, one battery, a
bulb, and a switch, can you get the
bulb to light up when the switch is
closed but turn off when the switch
is open?
Use symbols to draw your setup.
Open and Closed Circuits
•
An open circuit does not
allow the flow of electricity
(lights turned off)
•
A closed circuit allows the
flow of electricity (lights
turned on).
2 Types of Circuits

Series circuits
(Christmas lights)
are all wired
together to the
power source. If
one bulb goes out,
they all go out.

Parallel circuits
(store signs) are
wired separately to
the power source. If
one bulb goes out,
the others stay on.
DO NOW: Using symbols from
yesterday (page 3)
1. Draw an open circuit with 6
resistors.
2. Draw a closed circuit with 4 resistors
and 2 power sources.
3. Draw a closed circuit with 5
resistors.
glogster
What happens if one bulb goes out?
Series
Parallel
Why do you think your appliances at home are connected in parallel circuits?
Conductors





Metals are good conductors of electricity
(for example: wires)
They CONDUCT, or pass along, electricity
Plastic is a poor conductor, or insulator, of
electricity (covers the wires).
INSULATORS do not conduct, or pass along,
electricity
BBC website http://www.bbc.co.uk/schools/scienceclips/ages/8_9/circuits_conductors_whatnext.shtml
Reflection Journal questions
1. Why do you think electrical wires are
made of metal?
2. Why are electrical wires covered with
plastic?
3. How are electrons related to
electricity? (remember our game?)
4. Thinking question: How could you
use a circuit to test if something
passed along electricity?
Do Now:
 Work with your elbow buddy.
 Using the materials at your desk, and
your knowledge of science, make the
paperclips attract to the nail.
Do Now
 Write 2 sentences about what you learned about yesterday.
 Use the following terms:
Conductor insulator electricity
electrons
tightly-bound
 You have 3 minutes.
 ____________________________________________
____________________________________________
____________________________________________
____________________________________________
Electromagnets
 Brainpop
 brainpop/electromagnetic induction/