Emily Walak ECE 380-2 Current Attractions Essays - Electromagnetism

Emily Walak ECE 380-2 Current Attractions Big Idea: Electromagnetism is magnetism created by current flowing through a conductor. Electromagnets can be turned on and off. The strength of the magnetism produced by an electromagnet can be varied. Essential Questions: How can you make a magnet that turns on and off? PA Learning Standards S4.C.2.1.1 Recognize or illustrate simple direct current series and parallel circuits composed of batteries, light bulbs (or other common loads), wire, and on/off switches. Vocabulary magnet - an object that sticks to iron electromagnet - a piece of iron with insulated wire wrapped around it core - the material around which a coil is wound coil - a wire wound repeatedly around a central core Resources: FOSS Electricity and Magnetism Kit Materials: Each group needs 1 Rivet 1 electromagnetic wire, 24-gauge, 150 cm 1 short wire, 20 gauge, 15 cm 1 circuit base 1 D-cell, alkaline 1 switch 50 small washers, 1 cm diameter 1 plastic cup For the Class 1 wire stripper 1 magnet, doughnut shaped Grouping: Partners Engage: Tell students, I was thinking about a big old junkyard crane that I once saw. The crane used a big magnet to lift cars and put them on train cars. The crane operator could turn the magnet on and off! Can you make a miniature junkyard crane that turns on and off? Pour a cup of the small washers into one of the wells on a circuit base. Use a magnet, a steel rivet, and the washers to demonstrate the following. Discuss what is happening in each demonstration. Use a doughnut shaped permanent magnet to pick up the washers and move them to the opposite well. Use the magnet to pick up the rivet. Use the rivet stuck to the magnet to pick up the washers. Use the rivet by itself to pick up washers. Tell students, this is a steel rivet, but it isn't a magnet. Can you make a rivet like this into a magnet that will turn on and off? Explore: There is a new longer wire at the materials station for each team. The long wire may be useful for making your rivet into a magnet that turns on and off. Test the rivet for magnetism by trying to move the washers. When students have successfully constructed electromagnets, call for attention and ask students to make sure their switches are open. Ask, how did you make a magnet that could turn on and off? Explain: Tell students, you discovered an electromagnet. An electromagnet is a piece of iron with insulated wire wrapped around it. While electric current is flowing through the wire, the piece of steel becomes a temporary magnet. An electromagnet is made up of a core and a coil. The core is the rivet and the coil is the wire Extend/ Elaborate: Find the best electromagnetic design. Tell the students that just about everyone wound the wire around their rivets in a different way. Challenge them to work in their group to find the best location to wrap the wire on the rivet to make the rounded head of the electromagnet as strong as possible. Set standards for the class. Work with students to set some standards so that everyone will be able to compare results. Students should agree to always use the same number of winds, pick up washers on the head of the rivet, and count the washers lifted to determine the strength of the magnet. Evaluate: Ask each group to report how they wrapped the wire to produce the strongest magnet. They should report that the magnetism is strongest when the wire is wrapped close to the head, particularly between the first rubber washer and the head. Take Home Extension. N/A Reflection: Walk around while students are completing the activity and assist them as needed.

Samarium Facts - Sm or Element 62

Samarium Facts - Sm or Element 62 Samarium or Sm is a rare earth element or lanthanide with atomic number 62. Like other elements in the group, it is a shiny metal under ordinary conditions. Here is a collection of interesting samarium facts, including its uses and properties: Samarium Properties, History, and Uses Samarium was the first element to be named in honor of a person (an element eponym). It was discovered in 1879 by  French chemist Paul Émile Lecoq de Boisbaudran after he added  ammonium hydroxide to the preparation made from the mineral samarskite. Samarskite gets its name from its discoverer and the man who loaned Boisbaudran the mineral samples for his study Russian mining engineer  V.E. Samarsky-Bukjovets.Ingesting the right dose of samarium chloride will allow it to bind with alcohol and prevent you from getting intoxicated.Its unknown exactly how toxic samarium is. Its insoluble compounds are considered non-toxic, while the soluble salts may be mildly poisonous. There is some evidence samarium helps stimulate metabolism. It is not an essential element for human nutrition. When salts of samarium are ingested, only about 0.05% of the element is absorbed, while the rest is immediately excreted. Of the absorbed metal, about 45% goes to the liver and 45% is deposited onto bone surfaces. The remainder of the absorbed metal is eventually excreted. The samarium on bones remains in the body for around 10 years. Samarium is a yellowish silver-colored metal. It is the hardest and the most brittle of the rare earth elements. It tarnishes in air and will ignite in air  at about 150  °C.Under ordinary conditions, the metal has rhombohedral crystals. Heating changes the crystal structure to hexagonal close-packed (hcp). Further heating leads to a transition to a body-centered cubic (bcc) phase.Natural samarium consists of a mixture of 7 isotopes. Three  of these isotopes are unstable but have long half-lives. A total of 30 isotopes have been discovered or prepared, with atomic masses ranging from  131 to 160.There are numerous uses for this element. It is used to make  samarium-cobalt permanent magnets,  samarium X-ray lasers, glass that absorbs  infrared light, a catalyst for ethanol production, in the manufacture of carbon lights, and as part of a pain treatment regimen for bone cancer. Samarium may be used as an absorber in nuclear reactors. Nanocrystalline  BaFCl:Sm3 is a high ly sensitive x-ray storage phosphor, which may have applications in dosimetry and medical imaging. Samarium hexaboride, SmB6, is a topological insulator that may find use in quantum computers. The samarium 3 ion may be useful to make warm-white light-emitting diodes, although low quantum efficiency is an issue. In 1979, Sony introduced the first portable cassette player, the Sony Walkman, made using samarium cobalt magnets.Samarium is never found free in nature. It occurs in minerals with other rare earths. Sources of the element include the  minerals monazite and bastnasite. It is also found in samarskite, orthite, cerite, fluorspar, and ytterbite. Samarium is recovered from monazite and bastnasite using ion exchange and solvent extraction. Electrolysis may be used to produce pure samarium metal from its molten chloride with sodium chloride.Samarium is the 40th most abundant element on Earth. The average concentration of samarium in the Earths crust is 6 parts per million and about 1 part per billion by weight in the solar system. The elements concentration in seawater varies, ranging from 0.5 to 0.8 parts per trillion. Samarium is not homogeneously distributed in soil. For example, sandy soil may have a samarium concentration 200 times higher at the surface as compared with deeper, damp layers. In clay soil, there may be over a thousand times more samarium at the surface than further down. The most common oxidation state of samarium is 3 (trivalent). Most samarium salts are pale yellow in color.An approximate cost of pure samarium is about $360 per 100 grams of metal. Samarium Atomic Data Element Name:  SamariumAtomic Number:  62Symbol:  SmAtomic Weight:  150.36Discovery:  Boisbaudran 1879 or Jean Charles Galissard de Marignac 1853 (both of France)Electron Configuration:  [Xe] 4f6  6s2Element Classification:  Rare earth (lanthanide series)Name Origin:  Named for the mineral samarskite.Density (g/cc):  7.520Melting Point ( °K):  1350Boiling Point ( °K):  2064Appearance:  Silvery metalAtomic Radius (pm):  181Atomic Volume (cc/mol):  19.9Covalent Radius (pm):  162Ionic Radius:  96.4 (3e)Specific Heat (20 °C J/g mol):  0.180Fusion Heat (kJ/mol):  8.9Evaporation Heat (kJ/mol):  165Debye Temperature ( °K):  166.00Pauling Negativity Number:  1.17First Ionizing Energy (kJ/mol):  540.1Oxidation States:  4, 3, 2, 1 (usually 3)Lattice Structure:  RhombohedralLattice Constant (Ã…):  9.000Uses:  Alloys, magnets in headphonesSource:  Monazite (phosphate), bastnesite References and Historical Papers Emsley, John (2001). Samarium. Natures Building Blocks: An A–Z Guide to the Elements. Oxford, England, UK: Oxford University Press. pp. 371–374. ISBN 0-19-850340-7.Weast, Robert (1984).  CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp.  E110.  ISBN 0-8493-0464-4.De Laeter, J. R.; Bà ¶hlke, J. K.; De Bià ¨vre, P.; et al. (2003). Atomic weights of the elements. Review 2000 (IUPAC Technical Report).  Pure and Applied Chemistry. IUPAC.  75  (6): 683–800.Boisbaudran, Lecoq de (1879).  Recherches sur le samarium, radical dune terre nouvelle extraite de la samarskite. Comptes rendus hebdomadaires des sà ©ances de lAcadà ©mie des sciences.  89: 212–214.