Driving Question
Why do our clothes stick together when they come
out of the dryer?
Van De Graaf Generator
Watch the video
Write down 2 observations and 2 questions.
Driving Question Board
Post-it's:
Individually
Write down questions that will help us answer our driving
question:
● Why do clothes stick together when the come out of the dryer?
● Why did the pie tins do that???
One question per post-it
2-5 questions per person
Driving Question Board
Post-it's:
Groups
● Share questions with your group and
prioritize your 5 best questions
● As we share out our questions with the
class, think of how we can categorize the
questions. Does someone have a question
similar to yours?
Pie Tin Models
In your science journal,
create a model answering the
question: “Why did the pie
tins fly off of the Van De
Graaff generator?” I am not
looking for the correct
answer, just our “first draft.”
Initial Models (Warm up)
Create three drawings that help to explain why you think clothes stick together when they come out of the dryer.
Add to what is in the pictures below. Also include an explanation using complete sentences.
Before Drying
Explanation:
During Drying
After Drying
Please grab your whiteboards from yesterday.
Finish up any last touches you need to make to
your model.
Interactions
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Class Word = chem2019
Static Electricity Experiments: Interactions
Activity 3
Chemistry Warm-Up
Please complete on yellow sheet.
Last night’s reading said the following,
“One of the characteristics that makes these polyester materials
more effective for picking up dust is that their surface is not
smooth, but is covered with very fine fibers.”
Why does having small fibers make it easier for
the duster to electrically attract more dust?
You may refer to the reading to come up with an answer.
Static Electricity Experiments: Interactions
Activity 3
For the can experiment:
Describe what happened (pure observations)
In the can experiment, I noticed….
Explain what happened (try to explain WHY)
I think this happened because...
Static Electricity Experiments:
Interactions Activity 3
Draw a model that shows why the can moves
toward your the plastic strip only after it has been
rubbed with silk.
Plastic Strip-Can Before Rubbing with Silk
Plastic Strip-Can After Rubbing with Silk
Chemistry Warm-Up
Complete the warm-up on your yellow sheets.
A) Two charged objects approach each other and
suddenly stick together. What can you
conclude about their charges?
B) Two charged objects approach each other
and repel from each other. What can you
conclude about their charges?
Summary Table
What did we do?
What did we observe?
What patterns did we
notice?
What did we figure out?
How does this relate to
the phenomenon?
Continuous vs. Particle
Interactions Investigation 3 Activity 1
Can the same piece of paper be cut into pieces
indefinitely?
Complete on computer with partner.
Continuous vs. Particle
Continuous Model = matter is smooth. It can
be divided forever and it will still be the same.
The smallest part will be the same as what you
started with. Does not contain particles.
Particle Model = Matter is made from tiny
particles. If you continue to divide it, you will
have sub-particles that are different than what
you started with.
Mixing Liquids Lab
Follow instructions in packet.
Class Data on Board.
Complete Interactions Investigation 3 Activity 2 (concord)
(skip step 1 on initial ideas)
Does 5 + 5 always equal 10?
Matter
Matter = anything that has mass and takes up
space.
Steps of our Understanding
Where it all started:
John Dalton’s Model
Dalton believed that the atom was similar to a
billiard ball, just mass units.
Steps of our Understanding
Who is hungry?
J.J. Thomson’s Plum Pudding Model
Thomson used the Cathode Ray experiment to
propose that the atom
contained negative electrons
that are in a positively
charged “soup.”
Cathode Ray Experiment
How did this show electrons?
Steps of our Understanding
Gold is good for more than just jewelry.
Rutherford’s Gold Foil Experiment
Rutherford used his Gold Foil Experiment and
found something extremely interesting, what
do you think it was?
Positive protons packed CLOSELY together...
Rutherford was really surprised by the results of his experiment and
calculations. Based on what you know about interactions between charged
particles, why would scientists be surprised that a nucleus consists of positive
charged protons packed closely together in a tiny space?
Gold Foil Experiment
Steps of our Understanding
Niels Bohr gave us one of our last steps.
When finding the mass of atoms, something
did not add up…
If I told you that a proton’s mass was 1 amu,
and an electron’s mass was so small, we did
not count it, fill out the graph on the next slide.
One more mystery to solve...
Particle
Proton
Electron
Hydrogen Atom
(1 proton + 1 electron)
Helium Atom
(2 protons + 2 electron)
Lithium Atom
(3 protons + 3 electrons)
Carbon Atom
(6 protons + 6 electrons)
Picture
Mass
1 amu
0 amu
(sooo small it rounds to zero)
1 amu
(1 + 0 = 1)
One Last Big Concept
Erwin Schroodinger brought up this idea
Steps of our Understanding
In recap of what we have learned
Steps of our Understanding
How to draw Bohr’s model.
Spectral Lines
Related to Bohr Model
Atoms, Ions, Isotopes
Atom: Neutral in Charge
Ion:
[Protons = Electrons]
Charged molecule either positive or negative.
The element will have more or less ELECTRONS.
[Protons ≠ Electrons]
Isotope: An atom of the same ELEMENT with a
different number of NEUTRONS.
Proton, Neutrons and Electrons
Charge
Proton
Neutron
Electron
Relative Mass
Location
Inside the Atom
Mass of the Atom = Protons + Neutrons
Atomic Number = # of Protons
Neutrons = Atomic Mass – Atomic Number
Atoms, Ions, Isotopes
Nuclear
Symbol
Protons
Electrons
Neutrons
14
C
14
N
-3
12
C
Practice
1. Determine the number of protons, electrons and neutrons
in,
(a) 210Pb
(b) 34S
(c)
16
O-2
Warm-Up
Element Name:___________
Atomic Number:___________
Mass Number: __________
Charge:___________
How to make it -2?________
How to make it +1?________
+2
Li
Sr
Atomic Number:
Atomic Number:
Mass Number:
Mass Number:
Protons:
Protons:
Electrons:
Electrons:
Neutrons
Neutrons
Why do the clothes stick together?
Before Drying
During/After Drying
Why does the neutral curtain attract the
charged shirt?
Curtain Before T-shirt came near
Curtain After T-shirt came near