Module 1

Structure of the AtomModule 1

Fundamental KnowledgeComponents

Energy levels, binding energy & electron transitions

Atomic electron(e-) structure & associated energy levels define chemical & radiation-associated properties

Properties of the nucleus determine its energy characteristics & changes w/in nucleus define its radioactive nature

Different transformation (decay) processes w/in nucleus determine type of radiation produced & nuclide classification

Fundamental Knowledge: Describe the components of the atom. Explain the energy levels, binding energy and electron transitions in an atom. For the nucleus of an atom, describe its properties, how these properties determine its energy characteristics and how changes within the nucleus define its radioactive nature. For an atom, describe how its electron structure and associated energy levels define its chemical and radiation-associated properties. Explain how different transformation (decay) processes within the nucleus of an atom determine the type of radiation produced and the classification of the nuclide.

2CompositionElectrons- chargeVery little mass compared to nucleus# of e- vs. # of protons

NucleusMade up of nucleonsProtons (+ charge)Neutrons (no charge)Held together with strong nuclear force

Detailed Curriculum: 1. Structure of the Atom 1.1. Composition Electrons Nucleus 1.2. Electronic Structure Electron Orbits Orbital Nomenclature Binding Energy Electron Transitions Characteristic Radiation Auger Electrons 1.3. Nuclear Structure Composition Nuclear Force Mass Defect Binding Energy Nuclear InstabilityOverview

3Timeline of the Atom

Democritus 460BCDalton 1803 ADThomson 1897Rutherford 1912Bohr 1913Modern Quantum Cloud Model post 1930From the Greek a-tomos: indivisibleSolidDiscovery of e-+ substance w/ e- imbeddedDiscovery of + Nucleus; Point-like; most of mass; e- orbitingQuantized e- orbital modelMostly empty space w/ tiny massive nucleus w/ p+ & n;Cloudlike region of e-Ernest Rutherford (1871-1937)Contributions: Ernest Rutherford is considered the father of nuclear physics. With his gold foil experiment he was able to unlock the mysteries of the atomic structure. He received the noble prize in chemistry in 1908. In 1909 at the University of Manchester, Rutherford was bombarding a piece of gold foil with Alpha particles. Rutherford noted that although most of the particles went straight through the foil, one in every eight thousand was deflected back. "It was as if you fired a fifteen inch naval shell at a piece of tissue paper and the shell came right back and hit you," Rutherford said. He concluded that though an atom consists of mostly empty space, most of its mass is concentrated in a very small positively charged region known as the nucleus, while electrons buzz around on the outside.Rutherford was also able to observe that radioactive elements underwent a process of decay over time which varied from element to element. In 1919, Rutherford used alpha particles to transmutate one element (Oxygen) into another element (Nitrogen). Papers at the timed called it "splitting the atom."

4Rutherfords gold foil experiment

"It was as if you fired a 15 naval shell at a piece of tissue paper & the shell came right back & hit you" -Rutherford

e-Thompsons ModelUniform + chargeExpected Result:Actual Result:

Rutherfords ModelErnest Rutherford (1871-1937)Contributions: Ernest Rutherford is considered the father of nuclear physics. With his gold foil experiment he was able to unlock the mysteries of the atomic structure. He received the noble prize in chemistry in 1908. In 1909 at the University of Manchester, Rutherford was bombarding a piece of gold foil with Alpha particles. Rutherford noted that although most of the particles went straight through the foil, one in every eight thousand was deflected back. "It was as if you fired a fifteen inch naval shell at a piece of tissue paper and the shell came right back and hit you," Rutherford said. He concluded that though an atom consists of mostly empty space, most of its mass is concentrated in a very small positively charged region known as the nucleus, while electrons buzz around on the outside.Rutherford was also able to observe that radioactive elements underwent a process of decay over time which varied from element to element. In 1919, Rutherford used alpha particles to transmutate one element (Oxygen) into another element (Nitrogen). Papers at the timed called it "splitting the atom."

5StructureuududdudduudNucleus~10-14 mQuark