Mon 9/24 and Tues 9/25
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Transcript of Mon 9/24 and Tues 9/25
Mon 9/24 and Tues 9/25
• Test-Topography and Mapping today.
Pg.
Title Page for Ch. 30
In: pg
Quick write-2 minutesThe 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
proton
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+ 0
Notes-Atom Review
Thru 1-pg Cornell Notes
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
OutArrange the following from smallest to
largest.
CompoundAtomMoleculeNucleusSubatomic 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: pg1. Do a sketch of fission and fusion.2. Write down the definition for each
Nuclear fission-the nucleus of an atom splits apart into smaller nuclei, releasing energy.
Nuclear fusion-nuclei of smaller atoms join together to form a 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 Energy-Fission or Fusion Cloze
Video clip
Out
NuclearFission
NuclearFusion
In: pgHerztsprung-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 2Pg. 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.
Key1=nebula2=massive star3=solar-type star4=red giant5=supernova6=white dwarf7=neutron star8=black hole9=black dwarf
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.
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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”.
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 theoryA 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 well-known 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 20th-century 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 BalloonRead 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