Bohr-Rutherford model of the atom: nucleons: particles located in the nucleus of an atom proton, p + : positively charged (given by atomic #) neutron, n 0 : no charge (found by subtracting atomic # from mass #) electron, e : negatively charged, orbits the nucleus (given by atomic #) ground state: ‘normal’ state of an electron at its lowest energy level (orbital) excited state: when an e gains energy and moves to higher orbital than normal
Periodic Table Form
Standard Form
Isotopes: Different atoms of the same element may have different numbers of neutrons, which changes the mass of the atom (but not the type of element). Since neutrons are neutral, the element’s charge and chemical behaviour is unchanged. ex) Carbon-12 refers to the most common form of Carbon-14 has a mass number of 14. Calculate how many subatomic particles it has below: Carbon. Calculate how many subatomic particles it has below: protons: electrons: protons: electrons: neutrons: neutrons:
Radioisotopes are unstable isotopes that give off radiation. The radioisotopes undergo spontaneous changes of their nuclei (nucleuses), a process that releases energy (in the form of radiation).
One application of this is in medical imaging- see pg. 321
Radioactivity: the process by which the nucleus of an atom spontaneously changes its nucleus.
Nuclear Fission: the decomposition (splitting or breaking down) of a large, unstable nucleus into smaller, stable nuclei.
Strong Nuclear Force: the force that holds nucleons (protons and neutrons) together in the nucleus. Must be strong enough to overcome the repulsion of the protons.
Electrostatic Force: the force of attraction or repulsion due to electric charges. This both holds the electrons in orbit around the nucleus and also keeps them as far away as possible from each other.

In every atom there is a balance between the repulsive electrostatic force between the protons in the nucleus and the attractive strong nuclear force. Atoms with more protons have a higher electrostatic force and require more neutrons to counteract it.
An unstable atom is one that has a stronger electrostatic force than strong nuclear, so its nucleus may suddenly disintegrate. That disintegration is known as radioactive decay, and that atom is said to be radioactive.
There are different types of radioactive decay, and we have different nuclear reactions for them:
Review: Chemical Reactions C + O
2
 CO
2
+ energy
The above chemical reaction shows the synthesis of carbon dioxide from its elements. Energy is produced.
Nuclear Reactions: Equations that show us how the nucleus of an atom changes
In a nuclear reaction the parent atom is like the reactant and the daughter atom or atoms is like the product.
If a nuclear decay process produces a daughter atom of a different element than a parent atom
transmutation has occurred.
Alpha Decay: Read pg. 325, copy down the example and nuclear equation, and define any new bold terms.
Beta Decay (3 types): Do the same for pages 326 and 327
Gamma Decay: pg. 328
Characteristics of Radioactive Decay: Alpha and Beta particles and Gamma rays can all be dangerous
Type of decay alpha
Radiation Emitted particle Electric Charge alpha particle helium nucleus beta-negative beta particle electron beta-positive beta particle positron
+2
-1
+1 electron capture none gamma none gamma rays photon n/a
0 lead
Penetrating Ability skin or paper aluminum foil aluminum foil n/a
The timing of the decay of a radioactive nucleus is impossible to predict, but we can measure the rate of decay for a large sample of radioactive material.
Half-life is the time it takes for half of a radioactive material’s mass to undergo radioactive decay. It does not tell us the time for any one atom to decay; rather it is an average measure.
Carbon dating uses the half-life of Carbon-14 to determine how old ancient samples are. See pg. 332 for details.
Law of Conservation of Mass-Energy: Mass can transform into energy and energy can transform into mass.
The total mass-energy in a closed system (and in the universe) is constant.
This seems like a violation of the conservation of energy, but Einstein demonstrated these laws mathematically and they have been experimentally verified.

The equation E = mc 2 shows us the conversion of mass to energy. c is the speed of light, which is
3.0 x 10 8 m/s. This means that 1 kg of mass converted to energy would provide a lot of energy.
This equation allows us to explain a small problem in physics: An atom’s actual atomic mass is always slightly less than the mass of all of its protons, neutrons, and electrons. This phenomena is known as mass defect; the missing mass is present in the binding energy that is required to hold the nucleus together.
Nuclear Power Generation: Nuclear power is powered by nuclear fission (the splitting of an atom), which releases the binding energy of that atom’s nucleus. Some radioactive isotopes, such as uranium-235, undergo nuclear fission when struck by a neutron. These are called fissionable isotopes, and are used as nuclear fuel in fission reactors. Nuclear fission is very efficient; mass for mass, it produces 7 million times the energy of a dynamite explosion.
Write a nuclear equation for the reaction on pg. 336
The neutrons released from the fission reaction can cause other isotopes to undergo fission. If enough fuel is present, a chain reaction can occur. The amount of nuclear fuel required to start a chain reaction is called the
critical mass.
The Canadian-designed CANDU reactor uses heavy water, which is water made with an isotope of hydrogen, to control the fission reaction and create a controlled chain reaction. See pg. 339 for more information.
Nuclear fission powers some of our power plants. Nuclear fusion, the joining of two nuclei to create a new element, is what powers stars. Fusion is the opposite of fission, and is a much cleaner reaction, but much more difficult to control. See pages 345 and 346 for some attempts.
Research Project Ideas
Medical Imaging Techniques
Carbon Dating Techniques
Other technological applications of radioactivity
Physics (and biology) of radiation poisoning
Nuclear physics in weapons
Physics of a CANDU reactor
Physics of a nuclear submarine
Dangers of nuclear power generation
Politics of Iran’s nuclear program
Physics of nuclear fusion in stars and star life cycle
Problems with nuclear fusion in power generation
Environmental impact of nuclear fission power generation
Myth of cold-fusion*
Nuclear pest-control (pg. 348, 349 in textbook)

Nuclear Energy is an important topic that does not fit in well with the rest of the course. As such, it will not be covered on the unit test or the final exam, but will be evaluated with an independent research project instead.
It will be marked on thinking and communication categories.
Purpose: Learn about nuclear energy by researching a related topic that is of interest to you, and preparing a paper on what you have learned.
Methods: You will conduct a preliminary literature search (likely using the internet) to pick a topic, then select two or three sources to use to write your paper. You must cite your sources (see below).
Outcome: You will give background information on a topic, explore parts of a topic in some detail with reference to nuclear physics, and then discuss its impact on society or possible future directions.
Length: 3 – 5 pages double-spaced 12-pt font, not including Works Cited. If you think you are going to be under or over this word count please talk to me as the assignment progresses. You may include appropriate diagrams; if you do they should clearly connect to, and be explained in, your text.
Format: Your paper will include the following sections. The sections do not need to be labeled.
Introduction: 1 – 3 paragraphs that gives background information on your topic and outlines the parts of it that you are going to cover (kind of like a hypothesis or thesis statement, but you don’t have to be proving a point).
Body: Paragraphs explaining the science and impact of different parts of your topic
Conclusion: 1 – 2 paragraphs that summarize your information, discuss its impact on society and/or technology, and speculate on future directions or innovations
Works Cited: Lists all the information you used in your paper (not everything you looked at) in alphabetical order.
Sources: In a research paper, most of the information you are presenting is not your own. Research papers are important in science; they are used to find important information, and link information that may otherwise not be used together. Proper citation is very important to avoid plagiarizing material.
In-text citations: When you quote or refer to something in your paper, you put in a small reference right there, such as (Schweitzer, 2015). The full citation is located on your Works Cited page at the back of your paper.
Works Cited: Contains full citation information. We’re going to use APA format; see the website http://www.lib.uwo.ca/files/styleguides/APA.pdf for rules and examples. Ask for help if you have any questions/problems.
Good Online Sources: University web pages, Government web pages, well-known institutions web sites
Bad Online Sources: Jonny’spersonalguidetonuclear.org