By Kayla Westling

Hour 1
Mr.Voight
Science

Refernces

Objective I- What causes change??

Interactions of particles in different parts of atoms cause many different changes. In reactions, such as nuclear or chemical, they are of one or more particles reacting with other particles to form completely new substances. Or in a thing like nuclear fission or fusion, two or more particles either break apart or come together to change the identity and some characteristics of the product. And finally, in isotopes, the rate of release either allows us to harness the change, or for the change to become an outrageous disaster. These are all just a few of the ways that change occurs in out world and in science.

Objective H- Patterns


There are many patterns that help us in science. When doing nuclear equations, you know that it is nuclear, not because it has the same types of elements, but because the mass numbers and atomic numbers are equal on both sides. Whereas in a chemical equation, there are the same amounts and same types of each element on each side of the equation. Also, in the chain reaction above, Uranium-235 goes through nuclear fission and produces Barium-142 and Krypton-91 along with 3 neutrons.As the neutrons travel out, they hit other Uranium atoms, causing them to react, and the process to continue. The neutrons of the new reaction than go on to continue the process and the patten keeps on going. (each of the 3 neutrons produced travels out another Uranium atom, causing them to react.) So nuclear chain reactions show patterns is the ways the energy is released.

Objective F- Radiation produced by Nuclear Reactions

There are three main types of radiation. ALPHA, BETA, and GAMMA.

Alpha: The emission of a helium particle ptripped of its electrons. The resulting nucleus has a charge loss of two and a mass loss of four. Alpha particles have charges of +2. Kinetic energy emitted by an alpha particle, when impacting near particles, usually causes reactions in those molecules. Alpha particles are capable of doing the most damage, and are the most massive. But it cannot penetrate out skin, but after becoming gaseous it can go directly into the lungs and cause cancer.
238 234 4
92 U ==> 90 Th + 2 He is an alpha decay equation.

Beta: the emmision of high energy electrons from the nucleus of an atom. This process does nothing to the atomic mass, but the atomic number increases by one. In simplest terms, beta radiation changes a neurton into a proton. The charge is -1. It is more dangerous than alpha radiation but doesn't have the kinetic enerdy of alpha particles.
1 1 0 -
0 n ==> 1 p + -1e + v general equation for beta decay

Gamma: the emission of high energy photons in a certain range, with no matter associated with it. Gamma rays are normally the product of other beta or alpha emissions. They stabilize the nucleus by releasing some of the excess energy. Most damaging rays, are able to penetrate meter thick lead.



http://www.chemcases.com/nuclear/nc-14.htm
Pictures of radiation

Objective E- Benefits of isotopes

Here are some of the ways that isotopes can be beneficial to us. In medicine, radioactive isotopes are used in diagnosis as radioactive tracers or in scanning. They are used for scanning things such as the spleen, lungs, thyroid, and bones. Some are even used in treatments for cancers.
In agriculture, isotopes can also help us today. Radioactive isotopes are used in the agricultural industry as tracers in plants. They are added to fertilizers in small but known amounts. The researcher can then research the uptake by how radioactive the plant has become.
Radioactive isotopes can also be used in engineering. They are used in smoke detection, measuring its thickness. Another way of using radioactive isotopes is by using the rate of decay from machines to predict the wear of non-visible radioactive parts. Also, it is used to measure the radioactivity of lubricants in contact with machinery that is radioactive itself.
It can also be beneficial in other ways, but these are common uses.


Objective D- Radioactive isotopes

Atoms of the same element that differ in atomic masses are called isotopes. Mainly, the heavier atoms with the higher atomic numbers will have the number of neutrons within the core more likely to exceed the number of protons. Isotopes of the same element are often found in nature alternately or in mixtures. For example, in Chlorine-17 some contain 18 neutrons and some contain 20 neutrons, meaning the mass numbers would be 35 and 37 so it'd be 35Cl ans 37Cl. In these isotopes, a great number are unstable and will fall apart during radioactive decay processes. An isotope will be radioactive if its nuclei are unstable. Large atomic nuclei are usually unstable, and therefore, more likely to be radioactive. Small atomic nuclei can also be radioactive if the ratio of neutrons to protons exceeds certain limits.

Objective C- Energy released in Chemical and Nuclear Reactions

The difference between the amount of energy released in chemical reactions and nuclear reactions is HUGE!! Basically, the amount of energy released in chemical reactions is a peanut, where the amount of energy released in a nuclear reaction is an elephant. In chemical equations, there are two types, exothermic and endothermic. Exothermic- energy is released and endothermic- energy is absorbed. Where as in nuclear fission, the atoms nucleus splits apart. A tremendous amount of energy is released and the types of energy released are both heat and light energy. When it is let out slowly, it is harnessed to generate electricity. When it is let out quickly, a tremendous explosion occurs, such as in an atomic bomb. And in nuclear fusion, things are given off such as heat and light, and other radiation.
The energy generated by the fusion of hydrogen 2 in one gallon of water would almost equal the same amount of energy generated by the chemical change of burning 300 gallons of gasoline!

Objective B- Difference between Nuclear fusion and fission and Chemical reactions.

A chemical reaction can be described as the process by which one or more substances undergo a change to become one or more new substances. Where as a nuclear reaction is a reaction, as in fission or fusion or radioactive decay, that alters the energy composition or structure of the atomic nucleus. Here are some of the main diffences between the two subjects.


Six Differences between nuclear reactions and chemical reactions. Nuclear Reactions Chemical Reactions
1. Protons and neutrons react 1. Electrons react outside nucleus.
inside nucleus.
2. Elements transmute into other 2. The same number of each kind of
elements. atom appear in the reactants and products.
3. Isotopes react differently. 3. Isotopes react the same.
4. Independent of chemical 4. Depend on chemical combination.
combination.

5. Energy changes equal 10^8 kJ. 5. Energy changes equal
10 - 10^3 kJ/mol.
6. Mass changes are detectable. 6. Mass reactants = mass products.

Information provided by: http://vax1.bemidji.msus.edu/

Also, chemical reactions are very common and we often encounter them, whereas nuclear reactions are not so common. One can tell the difference between a chemical reaction and a nuclear reaction because in a chemical equation the LoCoM states that there are the same amount and same types of elements on each side. Where as in nuclear equations, there is not always the same element, but the atomic number and mass number are both equal on both sides.

Objective A- Nuclear Fusion

Nuclear fusion can be described as a nuclear reaction in which nuclei combine to form a more massive nuclei with the simultaneous release of energy. Fusion also forms an element with a higher atomic number, and is considered the reverse process of fission. Fusion of light elements (reactants) to heavier elements (products) along with the release of energy. When the mass of the products is less than the mass of the reactants, energy is released. (*the energy that is released is proportional to the difference is the mass-as predicted by Einstein's E=MC squared*). To occur, the reactants must be very close together- the nuclear forces bring the reactants together like glue. Also, fusion mostly occurs in a high density, low temperature environment. The reactants can also sometimes repel each other because of electrostatic force (similar to electromagnetic force). There is no limit to the amount of fusion that can occur, and the power that fuels our sun and stars is nuclear fusion. The balanced equations for nuclear fusion can be viewed at the website below.
This is the website that has numerous balanced nuclear equation, for both fusion and fission: http://www.lancs.ac.uk/ug/eardley/reaction_equations.htm
http://www.lancs.ac.uk/ug/eardley/reaction_equations.htm

Objective A- Nuclear Fission

Nuclear Fission can be described as the process of splitting atoms. When a nucleus goes through nuclear fission, it breaks apart into several different smaller pieces. These fission products, or pieces, are about half of the original mass. Also, a few neutrons are produced in the process. Fission can occur when a heavy atom's nucleus captures a neutron (or spontaneously). In the process of nuclear fission, when the nuclei split, energy is simultaneously released. Also, atoms decay by breaking into smaller, more stable nuclei is another way of describing nuclear fission. Some balanced equations for fission include the following:
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