Download S03 from fusion to all the elements.notebook

S03 from fusion to all the elements.notebook
November 21, 2012
The Elements: Forged in Stars
http://www.teachersdomain.org/resource/ess05.sci.ess.eiu.fusion/
Word bank
iron
supernova
carbon
neon
Note
neutrons
atoms
All matter is made up of ______­­ elements comprised of smaller particles such as ________, protons
________ , and ________ . The number of protons within the nucleus ­­ the central component of the electrons
isotopes
atom ­­ determines the type of ________ . An element can have different forms, called ________, based element
neutrons
on the number of ________ in the nucleus. For example, an ordinary hydrogen nucleus contains just one proton. But _________, an isotope of hydrogen, has one proton and one neutron in its nucleus.
deuterium
The entire universe shares a common set of elements. In the very early universe, the only elements were hydrogen
__________and__________ . But since the formation of stars, lighter elements within the stars began helium
fusing to create heavier elements, producing all the other naturally occurring elements. Under the extremely high temperatures and pressures within the core of stars, atoms collide at high enough speeds fusion
to overcome the usual electromagnetic repulsion of nuclei, allowing nuclear __________ to occur.
helium
All stars live by fusing hydrogen into _________. In the first step of the process, two hydrogen atoms deuterium
fuse to form __________. In the next step, another hydrogen atom fuses with the deuterium, creating a rare isotope of helium that has two protons and one neutron in its nucleus. In the third step, two of the rare helium atoms fuse to create a single normal helium atom and two hydrogen atoms. The fusion helium
hydrogen
pathway described above requires six____________ atoms to create one _________ atom ­­ however, there are two hydrogen atoms left over at the end of the process. The net result is that it takes four hydrogen atoms to make one helium atom. The energy that fuels a star is a result of the difference in Einstein's
mass between the original four hydrogen atoms and the resulting helium atom. Following __________ energy
E=mc2,
mass­energy relationship, ________ the missing mass is converted to _________.
At even higher temperatures and pressures, heavier elements are able to form. Many are made from a process called "helium capture," in which a heavier element fuses with a helium atom. For example, carbon
neon
helium fuses with ________ to make oxygen, and helium fuses with oxygen to make _______. Heavier nuclei can also fuse with each other, such as when carbon and oxygen fuse to make silicon or two iron
silicon atoms fuse to make _______. Eventually, the interior of a massive star begins to resemble an onion, with different elements being created in different layers. However, elements heavier than iron are only produced in the extraordinary conditions created by the collapse and explosion of a star ­­ a supernova
______________.
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S03 from fusion to all the elements.notebook
November 21, 2012
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S03 from fusion to all the elements.notebook
November 21, 2012
Spectroscopy and the stuff of stars
Spectroscopy is a tool used by astrophysicists to determine the composition of the stars. Light is produced when electrons jump from one orbital to another within an atom. These jumps are restricted to specific energy levels unique to each type of atom. When an astrophysicist uses a spectroscope, they can determine the elements present based on the "spectral" lines that are produced from the light they see. The following is taken from a question to an astrophysicists about the composition of our sun.
http://www.youtube.com/watch?v=­YYBCNQnYNM&feature=related
http://www.youtube.com/watch?v=QI50GBUJ48s
very detailed but difficult
short and simple
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961112a.html
Astronomers study the spectrum of the Sun to determine it's chemical composition. In the visible region alone, there are thousands of absorption lines in the solar spectrum. These lines have been cataloged, and tell us that there are 67 chemical elements identified in the Sun. There are probably even more elements in the Sun that are present in such a small amount that our instruments can't detect them. Here is a table of the 10 most common elements in the Sun: Element
Abundance (% of total # of atoms)
Abundance (% of total mass) Hydrogen
91.2
71.0
Helium
8.7
27.1
Oxygen
0.078
0.97
Carbon
0.043
0.40
Nitrogen
0.0088
0.096
Silicon
0.0045
0.099
Magnesium
0.0038
0.076
Neon
0.0035
0.058
Iron
0.030
0.014
Sulfur
0.015
0.040
You see that hydrogen is by far the most abundant element in the Sun, followed by helium. Those two together make up 99.9 percent by number of the total atoms in the Sun! This is also what we find in the composition of the Universe as a whole. Use the spectroscopes to examine the emission lines of the school's supply of gases.
In addition to determining the composition of objects in space, the motion of distant celestial objects can be analysed using spectroscopy along with the "Doppler Effect". Most of the stars view are "red shifted" indicating they are moving away from us. By tracing their paths, astronomers can work backwards to find their origin ­ the location of the big bang.
DOPPLER EFFECT
http://
www.youtube.co
m/watch?
v=Kg9F5pN5tlI
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