Transcript PS - Ch4_S1 student rev 2010PPT

4.1 Studying Atoms
Monday, October 11, 2010
3rd/4th/5th/7th periods - Have out notes and 15 openers for me to pick up.
3rd/4th - You should have pencil & 2 sheets of paper unless you already have done
your take home essay question. You will have calculator & reference sheet for testing.
#1-39 will be entered into the computer once you have finished those parts.
HW: Take Home Essay questions are due tomorrow... but may be turned in today.
6th period - Computer Activity Games - 6th period test tomorrow ch. 3
5th/7th period - Finish test part 2. Turn in take home essay questions.
Introduction to new unit. Notes 4.1 started....
ALL CLASSES: Turn in your computer activities GAME lab IN BOX.
4.1 Studying Atoms
Tuesday, October 12, 2010 - 6th period only...
6th period - Have out notes ch. 3 for me to pick up.
- You should have pencil & 2 sheets of paper unless you already have done your take
home essay question. You will have calculator & reference sheet for testing.
#1-39 will be entered into the computer once you have finished those parts.
HW: Take Home Essay questions are due tomorrow... but may be turned in today.
ALL CLASSES: Turn in your computer activities GAME lab IN BOX.
4.1 Studying Atoms
Tuesday, October 12, 2010 -3rd/4th periods only...
3rd/4th - Finish Questions #40-54. Turn in with Take Home essay question.
Introduction to new unit. Notes 4.1 started....
ALL CLASSES: Turn in your computer activities GAME lab IN BOX.
Introduction to Project...
Element Quiz - Friday, October 22nd over 53 element symbols/names...
4.1 Studying Atoms
I set up to automatically play short audio clip - song about atom/matter while you read
first 3 screens.
Studying the structure of
atoms is a little like studying
wind. Because you cannot see
air, you must use indirect
evidence to tell the direction of
the wind. Atoms pose a similar
problem because they are
extremely small. Even with a
microscope, scientists cannot
see the structure of an atom.
4.1 Studying Atoms
Ancient Greek Models of Atoms
If you cut a piece of aluminum foil in half,
you have two smaller pieces of the same
shiny, flexible substance. You could cut
the pieces again and again. Can you keep
dividing the aluminum into smaller
pieces? Greek philosophers debated a
similar question about 2500 years ago.
4.1 Studying Atoms
Ancient Greek Models of Atoms
The philosopher Democritus believed that
all matter consisted of extremely small
particles that could not be divided. He
called these particles atoms from the
Greek word atomos, which means “uncut”
or “indivisible.”
4.1 Studying Atoms
Ancient Greek Models of Atoms
Aristotle thought that all
substances were made of only
four elements—earth, air, fire, and
water. He did not think there was a
limit to the division of matter.
For many centuries, most people
accepted Aristotle’s views on the
structure of matter. By the 1800s,
scientists had enough
experimental data to support an
atomic model.
4.1 Studying Atoms
Dalton’s Atomic Theory around
1803
What was Dalton’s theory of the structure of
matter?
Dalton proposed the theory that all matter is
made up of individual particles called atoms,
which cannot be divided.
4.1 Studying Atoms
Dalton’s Atomic Theory
Evidence for Atoms
John Dalton studied the behavior of gases in
air. Based on the way gases exert pressure,
Dalton correctly concluded that a gas consists
of individual particles.
Dalton measured masses of elements that
combine when compounds form. The ratio of
the masses of the elements in each
compound was always the same. In other
words, compounds have a fixed composition.
4.1 Studying Atoms
Dalton’s Atomic Theory
When magnesium burns, it
combines with oxygen. In
magnesium oxide, the ratio of
the mass of magnesium to
the mass of oxygen is always
about 3 : 2. Magnesium
dioxide has a fixed
composition.
4.1 Studying Atoms
Dalton’s Atomic Theory
Dalton’s Theory
• All elements are composed of atoms.
• All atoms of the same element have the same mass,
and atoms of different elements have different
masses.
• Compounds contain atoms of more than one
element.
• In a particular compound, atoms of different
elements always combine in the same way.
• Example: there is always 1 C with 2 O’s in the
compound carbon dioxide, CO2.
4.1 Studying Atoms
Dalton’s Atomic Theory
Dalton made these wooden spheres as a model
to represent the atoms of different elements. A
tiny, solid sphere with a different mass
represents each type of atom. Dalton was the
first to use scientific evidence to explain the
model.
4.1 Studying Atoms
Dalton’s Atomic Theory
A theory must explain the data from many
experiments. Because Dalton’s atomic theory
met that goal, the theory became widely
accepted.
Over time, scientists found that not all of
Dalton’s ideas about atoms were completely
correct. They revised the theory to take into
account new discoveries.
4.1 Studying Atoms
Thomson’s Model of the Atom about 1897
Thomson experimented with the cathode ray
tube.
Thomson’s experiments provided the first
evidence that atoms are made of even
smaller particles.
note to me:
QUICK LAB PG. 102 WITH TRANSPARENT
TAPE BEFORE CONTINUING WITH NOTES.
scotch tape and scissors needed at each table...
4.1 Studying Atoms
Thomson’s Model of the Atom
When some materials are rubbed, they gain
the ability to attract or repel other materials.
Such materials are said to have either a
positive or a negative electric charge.
• Objects with like charges repel, or push apart.
• Objects with opposite charges attract, or pull
together.
4.1 Studying Atoms
Thomson’s Model of the Atom Cathode Ray Tube
Thomson’s Experiments
In his experiments, Joseph John Thomson
used a sealed tube containing a very small
amount of gas.
Sealed tube filled
Glowing beam
with gas at low
pressure
Metal disk
Metal disk
Source of
electric current
Metal disk
Source of
electric current
4.1 Studying Atoms
Thomson’s Model of the Atom
Thomson’s Experiments
In his experiments, Joseph John Thomson
used a sealed tube containing a very small
amount of gas.
Sealed tube filled
Glowing beam
with gas at low
pressure
Positive plate
Metal disk
Metal disk
Source of
electric current
Negative plate
Metal disk
Source of
electric current
4.1 Studying Atoms
Thomson’s Model of the Atom
When the current was turned on, the disks
became charged, and a glowing beam
appeared in the tube.
• Thomson hypothesized that the beam was a
stream of charged particles that interacted with
the air in the tube and caused the air to glow.
• Thomson observed that the beam was repelled
by the negatively charged plate and attracted
by the positively charged plate.
4.1 Studying Atoms
Thomson’s Model of the Atom
Evidence for Subatomic Particles
Thomson concluded that the particles in the beam had
a negative charge because they were attracted to the
positive plate. He hypothesized that the particles
came from inside atoms because
• no matter what metal Thomson used for the disk, the
particles produced were identical.
• the particles had about 1/2000 the mass of a hydrogen
atom, the lightest atom.
QuickTime™ and a
decompressor
are needed to see this picture.
Cathode tube: http://www.youtube.com/watch?v=7YHwMWcxe
with magnet...
4.1 Studying Atoms
Thomson’s Model of the Atom
Thomson’s Model
Thomson revised Dalton’s model to account
for these subatomic particles.
• The atom has neither a positive nor a negative
charge, but there must always be some positive
charge in the atom.
• The atom is filled with a positively charged mass
of matter that has negative charges evenly
scattered throughout it.
4.1 Studying AtomsThomson’s
Model of the Atom
Thomson’s model is called the
“plum pudding” model. Today, it
might be called the “chocolate
chip ice cream” model.
The chips represent negatively
charged particles, which are
spread evenly through a mass of
positively charged matter—the
vanilla ice cream. Thus, the
pudding has a positive charge
and the plums represent the
negative charge spread evenly
throughout.
4.1 Studying Atoms
Rutherford’s Atomic Theory
What contributions did Rutherford make to
the development of atomic theory?
According to Rutherford’s model, all of an
atom’s positive charge is concentrated in its
nucleus.
Rutherford discovered that uranium emits fastmoving particles that have a positive charge,
called alpha particles.
4.1 Studying Atoms
Ernest Rutherford Experiment in the words from a couple of high school students...
http://www.youtube.com/watch?v=YnfT7jODBYk
QuickTime™ and a
H.264 decompressor
are needed to see this picture.
4.1 Studying Atoms
Formal explanation video
http://www.youtube.com/watch?v=5pZj0u_XMbc&feature=related
4.1 Studying Atoms
Rutherford’s Atomic Theory
Rutherford’s Hypothesis
Ernest Rutherford designed an experiment to find out
what happens to alpha particles when they pass
through a thin sheet of gold.
• Based on Thomson’s model, Rutherford hypothesized
that the mass and charge at any location in the gold
would be too small to change the path of an alpha
particle.
• He predicted that most particles would travel in a straight
path from their source to a screen that lit up when struck.
4.1 Studying Atoms
Rutherford’s Atomic Theory
The Gold Foil Experiment
Deflected
particle
Alpha particles
Undeflected
particle
Gold atoms
Slit
Beam of alpha
particles
Alpha particles
Screen
Source of alpha
particles
Nucleus
4.1 Studying Atoms
Rutherford’s Atomic Theory
Discovery of the Nucleus
The alpha particles whose paths were
deflected must have come close to
another charged object. The closer
they came, the greater the deflection.
However, many alpha particles passed
through the gold without being
deflected. These particles did not pass
close to a charged object.
4.1 Studying Atoms
Rutherford’s Atomic Theory
Thomson’s model did not explain all of the evidence from
Rutherford's experiment. Rutherford proposed a new model.
Rutherford concluded that the positive charge of an atom is not
evenly spread throughout the atom.
Positive charge is concentrated
in a very small, dense central
area.
The nucleus of the atom is a
dense, positively charged mass
located in the center of the
atom. The alpha particles that
were deflected came very close
to a nucleus.
QuickTime™ and a
decompressor
are needed to see this picture.
4.1 Studying Atoms
Rutherford’s Atomic Theory
The Houston Astrodome
occupies more than nine
acres and seats 60,000
people. If the stadium
were a model for an atom,
a marble could represent
its nucleus.
The total volume of an
atom is about a trillion
(1012) times the volume of
its nucleus.
4.1 Studying Atoms
Read the following questions and THEN decide which scientist you and a partner
will select to illustrate the contributions the scientist made toward the
development of atomic theory...
4.1 Studying Atoms
Assessment Questions
1. Dalton’s theory did not include which of the
following points?
a.
b.
c.
d.
All elements are composed of atoms.
Most of an atom’s mass is in its nucleus.
Compounds contain atoms of more than one element.
In a specific compound, atoms of different elements
always combine in the same way.
4.1 Studying Atoms
Assessment Questions
1. Dalton’s theory did not include which of the
following points?
a.
b.
c.
d.
All elements are composed of atoms.
Most of an atom’s mass is in its nucleus.
Compounds contain atoms of more than one element.
In a specific compound, atoms of different elements
always combine in the same way.
ANS: B
4.1 Studying Atoms
Assessment Questions
2. J. J. Thomson’s experiments provided the first
evidence of
a.
b.
c.
d.
atoms.
a nucleus.
subatomic particles.
elements.
4.1 Studying Atoms
Assessment Questions
2. J. J. Thomson’s experiments provided the first
evidence of
a.
b.
c.
d.
atoms.
a nucleus.
subatomic particles.
elements.
ANS: C
4.1 Studying Atoms
Assessment Questions
31. #3. The concept of an atom as a small particle of
matter that cannot be divided was proposed by
the ancient Greek philosopher, Democritus.
True
False
4.1 Studying Atoms
Assessment Questions
1. #3. The concept of an atom as a small particle of
matter that cannot be divided was proposed by
the ancient Greek philosopher, Democritus.
True
False
ANS:
T
4.1 Studying Atoms
Partner Poster Project of Scientists of Atomic Theory...
Create a poster of one of the following scientist(s)... illustrating what they helped
contribute to the atomic theory...
Aristotle & Democritus
Dalton
Thomson
Rutherford
OTHER with approval...
Faraday, Mendeleev, Bohr, Millikan, Schrodinger, Chadwick, Heisenberg,
Einstein & de Broglie
There are colored pencils and markers available in blue tub in back by sink.
All drawings should take up most of a regular size copy sheet of paper and be in color.
Words may also be used to describe contribution.
4.1 Studying Atoms
WEDNESDAY - APRIL 7, 2010
Pick up computer and log-in... (V2 and V5 should be fixed...)
1. Have out your notes ch. 2 & 3 along with answer to ch. 3 problems on back of
notes with all work shown to turn in.
2. Have out your study guide answers to turn in.
3. Turn in endothermic, exothermic, oobleck and slime lab question/answers. (Some
have turned these in already but said to hold with openers.)
We will turn in the 15 openers tomorrow (not today please...)
TURN IN ALL ITEMS TOGETHER IN BOX... (They do not have to be stapled but
should all have your name on them.)
BRING SUPPLIES FOR DRY ICE - ICE CREAM - WE CAN’T DO WITH OUT SOME
MORE SUPPLIES... I NEED THESE BY FRIDAY TO SEE IF WE CAN DO.
Element names and symbols test will be on MONDAY!
SAT 10 TESTING FRIDAY - ANNOUNCEMENT FOR WHERE YOU GO - SEE LIST.
SIGN UP FOR YOUR ELEMENT TODAY WHILE TESTING...
ESSAYS WILL NOT BE DONE ON COMPUTER - DO ON PAPER.
4.1 Studying Atoms
Opener #15 - Tuesday - April 6, 2010 - Pick up remote control...
You do NOT have to write in complete sentences today only... but do
explain or show work where applicable...
Complete the questions Sect.
3.3 pg. 91 #1-8.
Have out ch. 3 questions (back of ch. 3 notes). We will go over answers.
If you did not show work, you will not get points but will turn in tomorrow
along with notes ch. 2 and notes ch. 3 for grade.
Be sure chapter 3 questions are turned in the BOX. If they are not turned
in today, they are considered late and will lose points.
We will turn in openers on Thursday just to keep my sanity along with the
quick lab with endothermic, exothermic, oobleck and slime lab if you
didn’t already turn in...
3-D atom due next Wednesday...
TEST tomorrow ch.2-3 -- QUIZ Friday (may be moved to Monday...)
Bring supplies for dry ice - ice cream... This may have to be changed to
Monday if we are TESTING on Friday with CAPS groups... (?)
4.1 Studying Atoms
Opener #14 - Monday - April 5, 2010
You do NOT have to write in complete sentences but do show work for math problems.
1. Complete Section
3.2 pg. 81 #1-10 as opener #14.
CW: Vocabulary Match Game reinforcement Activity...
3-D project introduction... with minor change in requirement... due Wed., April 14th...
CW: Notes 4.1
CW: Partner Poster Project with Scientists of Atomic Theory...due Thursday in class...
**Turn in ch. 3 assessment questions pg. 94-95-96 IN BOX before leaving today.
Be sure you have completed study guide questions by tomorrow if not done...
TEST on Wednesday over ch. 2-3...
Test on element symbols and names... You will be given name or symbol and have to
write the other... spelling does count... computer links are online at podcast page...
HW: Ch.2-3 Problems due tomorrow (see handout on notes ch. 2 and new handout...)