JOURNRL OF
Chemical Education: Software Abstract for Volume 7 C, Number 2 A Window on the Solid State I: Structures of Metals, 11: Unit Cells of Metals William R. Robinson Purdue University West Lafayette, IN 47907-1393 Christopher P. Saari Project SERAPHIM, University of Wisconsin-Madison Madison, WI 53706-1396
A Window on the Solid State for Macintosh is a translation of a Windows program previously published by JCE: Softwan (1).Part I: Structures of Metals introduces the fourbasic structural types found in metals: hexagonal closest-packed, cubic closesbpacked, body-centered cubic, and simple cubic structures. These are introduced as stacks of close-packed planes of atoms in the hexagonal and cubic closest-packed structures, and stacks of less efficiently packed planes in the other two structures. In addition, Part I also introduces Laves's principle, wordination number, stackingof planes, efficiencyof packing, and how to draw the structures usingtwodimensional representations.
Comparison of layers in hexagonal close-packed and cubic closepacked structures from A Window on the Solid State. the undergraduate level. These programs emphasize the qualitative and geometric aspects of the structures presented. Although no numerical calculations are requested in these programs, students will be well prepared to tackle quantitative exercises by the information presented.
Videodisc Player Utility Programs Videodisc Browser 2.0 Jerrold J. Jacobsen Univeffiity of Wisconsin-Madison Madison, WI 53706-1396
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Part II: Unit Cells of Metals discusses how to use a unit cell to describe a two-dimensional structure, then extends the concept to metals using the four basicunit cellsofthe metals. The relationships between radii ofthe metal atoms in the cubic structures A d the cell dimensions are developed. Students are also introduced to counting the number of atoms in a unit cell. Pseudo-animation is particularly effectivein illnstrating the fractions of atoms that lie in the various unit cells. Two venions of each part are provided. One is a student tutorial that allows a student to work through the material a t herhis own pace. This version requires students to identify or predict structural features and includes pop-up boxes that confirm or correct choices. Hot words are used to link ideas and provide definitions. The other version is designed to he used in lecture demonstration; it contains all graphics and summary statements from the tutorial nroeram. but is less interactive. ~ i t vkrsious h are intended as supplements to a n introductory mesentation. either a t the general chemistry level or a t the first introdktion of the h c t u r e s of metals a t 814
Journal of Chemical Education
The great strength of videodiscs for education is that they provide quick, random access to a large number of short video clips and images. However, the amount of material available can make it difficult to find the particular video clip or image that is needed. Computer control of the videodisc player can help by providing more convenient search capabilities and controlling video playback with the click of an on-screen button. Videodisc Browser 2.0 takes computerized videodisc control one step further by providing manv descri~tionsand wints of view of a videodisc. each design& for a'different way you can use video. It e& he used with any videodisc for which descriptive data are available and can he customized to meet individual needs. Videodisc Browser 2.0 automatically recognizes three JCE: Software videodiscs, The Periodic Table, ChemDemos, and Titration Techniques (2,3, 4). As new videodiscs are released by JCE: Software, text files allowing similar control capabilities will be developed for them.
Lesson Manager for Demonstrations in Organic Chemistry Videodisc Gary L. Trammell Scott Grlssom Sangarnon State Univerrity Springfield, lL 62794-9243 Lesson Manager for Demonstrations in Organic Chemistry Videodisc is a Hypercard (5)stack designed to enable high school and college chemistry teachers to have easy access to selections from.the Demonstrations in Organic Chemistry Videodisc (6). It enables selection of video seg-
