Transcript The Big Bang Theory

Mon 9/24 and Tues 9/25
• Test-Topography and Mapping today.
Pg.
Title Page for Ch. 30
In: pg
Quick write-2 minutes
The periodic table is…
Thru 1: Pg
Periodic Table Coloring Activity
• Pick one color for each family listed on the
back.
• Use the atomic # to color each square on
the periodic table the right color.
• Complete the blank key at the top of the
periodic table.
Out
Pick any 3 elements from the periodic table
and describe why you think they were
given the names they were.
Element
Reason for name
Wed. and Thurs
• Test-Topography and Mapping today.
In: pg
Sketch a model of an atom and label
ALL of its parts.
electron
__
neutron
+
0
proton
Thru 1-pg
Cornell Notes
Notes-Atom Review
Matter
• Matter is anything that has mass and
volume.
• Matter is made of atoms.
– May be atoms all of one kind--Elements
– May be atoms of different kinds bonded
together-Compounds
Atomic Models
Atom models
– Rutherford model
• mostly empty space
with nucleus at the
center & electrons
orbiting
– Bohr model
• electrons moving
in set paths that
determine their energy
levels
– electrons change
energy levels when
they gain or lose
energy
– Schrodinger model
• known as electron
cloud model
• electron position and
speed & direction are
described in terms of
probability
ATOMIC STRUCTURE
• Parts of an atom
– Proton
• positive charge
• located in the nucleus
• mass
– 1.67 x 10-27 kg =
1 atomic mass unit
(amu.)
– Neutron
• no charge
• located in the nucleus
• mass
– 1.67 x 10-27 kg = 1
amu
– Electron
• negative charge
• located outside the
nucleus
• mass 9.11 x 10-31 kg
= 0 amu
Neutral atoms
• Atoms may be
neutral (no
charge)
+protons=
-electrons.
Ions
• Atoms can be ions
(atoms with an overall
+ or – charge)
– An ion has gained or
lost an electron.
– Gaining an electron
gives the atom an
overall negative charge.
– Losing an electron gives
the atom an overall
positive charge.
Thru 2
• Fab-5 # 4—Story
Board..
– Create a Story Board for
the topic of ATOMS.
• Atom Practice Sheet
Out
Arrange the following from smallest to
largest.
Compound
Atom
Molecule
Nucleus
Subatomic particle (these are protons,
neutrons and electrons)
In:
Use the diagrams below to come up with your own
definitions of nuclear fission and nuclear fusion.
Thru 1: pg
1. Do a sketch of fission and fusion.
2. Write down the definition for each
Nuclear fission-the nucleus of an Nuclear fusion-nuclei of smaller
atom splits apart into smaller
atoms join together to form a
nuclei, releasing energy.
larger nucleus, releasing energy.
Nuclear Reactions
• Give off energy in the form of light, heat
and gamma radiation.
• Fission happens on Earth in nuclear
reactors and in naturally radioactive
elements found within the earth’s crust.
• Fusion occurs in the core of stars and is
the reason why stars shine and give off
heat.
Our sun
• Each second, the sun transforms 700
million tons of hydrogen gas into 695
million tons of helium gas through the
nuclear reaction of fusion. The
remaining 5 million tons of matter
(about 600 times the weight of water
flowing over Niagara Falls in one
second) escape as pure energy.
Thru 2
Pg.
Marie Curie and the
Naming of a Unit.
• Homework!!!
Pg.
Nuclear EnergyFission or Fusion
Cloze
Video clip
Out
Nuclear
Fission
Nuclear
Fusion
In: pg
Herztsprung-Russell Diagram
• Use the H-R diagram to answer the
following questions:
1. What is meant by the word “magnitude”?
2. What color are cooler stars?
3. What color are hot stars?
4. What are main sequence stars?
5. What category of star is our sun?
6. Using the diagram, how would you
describe our sun?
Herztsprung-Russell Diagram
Stellar Fusion
http://heasarc.nasa.gov/docs/xmm_lc/lessons/background-lifecycles.html
A star's life cycle is determined
by its mass. The larger its
mass, the shorter its life cycle.
A star's mass is determined by
the amount of matter that is
available in its nebula, the
giant cloud of gas and dust
from which it was born. Over
time, the hydrogen gas in the
nebula is pulled together by
gravity and it begins to spin.
As the gas spins faster, it
heats up and becomes as a
protostar.
http://www.nasa.gov/images/content/107455main_region_88_lgweb.jpg
Eventually the
temperature reaches
15,000,000 degrees
Celsius and nuclear
fusion occurs in the
cloud's core. The cloud
begins to glow brightly,
contracts a little, and
becomes stable. It is now
a main sequence star and
will remain in this stage,
shining for millions to
billions of years to come.
This is the stage our Sun
is at right now.
http://www.nrl.navy.mil/NewsRoom/images/sun.jpg
Thru 1: pg
The Life Cycle of Stars Flow Map.
Use the reading to fill in the spaces on the
flow map.
Thru 2
Pg. Analysis questions:
1. What is a nebula and what is its
role in the life cycle of a star?
2. What are 3 major differences
between a massive star’s and a
less massive star’s life cycle?
3. What is going to be the fate of
our sun? How do you know
this?
4. What do the most massive
stars become at the end of their
life cycle?
5. Why does a Black Hole have a
greater gravitational pull than a
Black Dwarf?
6. What is the source of energy
for all stars?
Pg.
Star Life Cycle
Diagram.
Key
1=nebula
2=massive star
3=solar-type star
4=red giant
5=supernova
6=white dwarf
7=neutron star
8=black hole
9=black dwarf
8
1
1
2
5
4
7
1
9
6
3
4
Diagram must include: 1. all stages of life,2. labels of stages of
life,3. color and 4. clear marking of Massive vs Low mass star life
cycles.
Out
• What do astronomers
mean when they refer
to the “life cycle” of a
star?
• How does this like a
human life cycle?
In: pg
Visible light questions:
1. What colors are on the visible light spectrum?
2. What units are the wavelengths of light measured in?
3. What is the range of wavelengths of visible light?
4. Which color has the longest wavelength?
5. Which color has the shortest wavelength?
6. What color would you expect to see at a wavelength of 0.45 micrometers?
7. What color would you expect to see at 0.7 micrometers?
• Each gas when illuminated gives off a
unique set of spectral lines “spectal
fingerprint”.
4
5
6
7
Thru 1: pg 69
Color the Spectrum Activity—don’t forget to
do the back!!
White Light
Hydrogen Emission Spectrum
Helium Emission Spectrum
Carbon Emission Spectrum
Hydrogen + Helium Emission
Spectrum
Out
• What is a spectral fingerprint?
• How does it help us understand stars?
In: pg
Before reading:
As humans, we form theories all of the time.
1.
What is a theory?
A scientific theory
A scientific theory is when scientists have tested a group of
related hypotheses many times and the hypotheses (remember, a
hypothesis is an explanation for an observations about nature)
are supported by data. Scientific ideas are not considered
theories until they are generally accepted principles that explain a
vast number of observations and experimental data. Examples of
scientific theories include: the Atomic Theory, the Theory of
Natural Selection, the Theory of Plate Tectonics as well as many
other widely supported and accepted scientific principles.
“They’re the big ideas in science,” explains Niles Eldredge, a
paleontologist at the Museum of Natural History. “They’re taken
very, very seriously.” Eugenie Scott, executive director of the
National Center for Science Education, says, “Theories explain
laws and facts. They’re the most important thing we do in
science.” And Ken Miller, a biologist at Brown University and wellknown lecturer on evolution, says a theory is the result of large
collections of facts put into an explanatory framework.
After the reading:
2. What is a scientific theory?
3. How do scientific theories differ from
the theories you form everyday?
The Big Bang Theory
• The Big Bang Theory is the dominant scientific theory
about the origin of the universe. According to the big
bang, the universe was created sometime between 10
billion and 20 billion years ago from a cosmic explosion
that hurled matter and in all directions. The original
matter was small and dense, but we don’t know what it
was.
• The big bang was initially suggested because it explains
why distant galaxies are traveling away from us at great
speeds. The theory also predicts the existence of cosmic
background radiation (the glow left over from the
explosion itself). The Big Bang Theory received its
strongest confirmation when this radiation was
discovered in 1964.
Big Bang Theory
• The universe was created between
10 - 20 billion years ago from a
cosmic explosion.
• The original matter was small and
dense, but we don’t know what it
was.
• It explains why distant galaxies
are traveling away from us at
great speeds=expanding.
• It also predicts the existence of
cosmic background radiation-the
glow left over from the explosion
itself.(1964)
4. What does the Big Bang Theory explain?
5. What are 2 pieces of evidence supporting
the Big Bang Theory?
The Expanding Universe
• More than anything else, breaking down the light
from celestial objects into its constituent colors
has helped us understand the universe. A
spectrum can tell astronomers what an object is
made of, how hot it is, how fast it is moving, and
a host of other important attributes.
Spectroscopy has revealed the great abundance
of hydrogen and helium in the universe—
providing observational support for the big-bang
theory—and showed the relative amounts of the
other elements since cooked up in stars.
Red-shifted Stars
•
Just as important, spectroscopy revealed the
expansion of the universe. When an object moves away
from us, the lines in its spectrum get displaced toward
longer wavelengths, with the amount of this so-called
redshift proportional to the object’s velocity. Edwin
Hubble first showed that the spectrum of almost every
galaxy is shifted to the red, and that the farther away the
galaxy, the greater the redshift. From these
observations, cosmologists correctly deduced that the
universe is expanding.
•
What would show that galaxies are getting closer to
us? Staying the same distance away? How would it be
possible to be staying the same distance away if the Big
Bang Theory was true?
• Edwin Hubble first showed that the
spectrum of almost every galaxy is shifted
to the red, and that the farther away the
galaxy, the greater the redshift.
• Red-shift shows that the universe is
expanding.
• Blue-shift would show objects moving
toward us.
Absorption lines in the optical spectrum of
a supercluster of distant galaxies (right), as
compared to absorption lines in the optical
spectrum of the Sun (left). Arrows indicate
redshift. Wavelength increases up towards
the red and beyond (frequency decreases).
Hubble’s Law
• By the late 1920s, Edwin Hubble had been taking
spectra and measuring distances to a large number of
galaxies. From each spectrum he learned the galaxy’s
redshift, which told him how fast it was moving away
from Earth, then he compared that with the object’s
distance. What he found set the stage for much of 20thcentury cosmology: the farther away the galaxy, the
faster it receded. This relation—that a galaxy’s speed is
directly proportional to its distance—became known as
Hubble’s Law. It was observational proof that we live in
an expanding universe, and it helped lay the foundation
for the big-bang theory of the universe’s origin.
Thru 1: pg
Big Bang Balloon
Read the direction sheet.
Follow the steps and complete the data
sheet.
Tape in the data sheet.
Out
1. What are the 2 pieces of
evidence that support the
Big Bang Theory?
2. Do you find them
convincing? Explain.
Study Guide
Pg. Answers
Pg. Questions