Computer Demonstrations The use of comouters in instruction,. oarticularlv as stimulated bv the advent of microcomouters. has been discussed . r x t e n s d y in thirand other journals.' Much ofthiracrivity involresa m e student-one terminal inlpractim, ususlly referred 11, as computer nsrrrted instructim !('Al,. Ikspite recent advancer, the n,st i n equipment and stair t u cundurt CAI in a large rour,e is still quite subrtantral. This note is tc, point out the potential use of m i c r w ~ m p ~ ~ast ea ~tad s ln performing lecture drmonstratimr nt a relatively m a l l cost. The monitor uutput of commmly awlahle mirrr,rm~puters(TKS-8l1.Apple, etc.1 is a sulndnrd 1'V vidiu iiannl. Man" claarnxxns already haw T V monitors which have a vidm rnot RF modulated, input. Assuming i t a h monitors are nvnilahle, for the roughly $CK capital cost of a microcomputer, computer simulations and graphics can &ily can easily be performed in class. A keyboard console and cassette recorder can be earried into class, literally under one's arm, and plugged into an existing monitor system. One computer per department should thus be sufficient, and need not be dedicated entirely to classroom use. Demonstrations by nature are rather short and simple. Thus programming these can be bite-size problems suitable as student projects. We have developed several programs suitable for classroom use, largely with the assistance of undergraduate programmers. One is a periodic table graphics program. This first draws lines to construct a table. Then the instructor may have displayed the symbol and atomic number of individual elements, rows, groups, andlor bloeks. This is particularly useful in discussing the use of the table in predicting electron configurations and periodic properties. Another program simulates the random diffusion of one gas into another, allowing variation of parameters representing T and N. A third program plots an acid-base titration curve for any realistic eomhination of K , and Kb. These programs are written in BASIC for a Level If TRS-80. Copies of listings are available from the author on request. 'See for example Moore, J., et al., J. CHEM. EDUC., 56,776 (1919) and references quoted therein. University of Florida Gainesville. FL 32611
702 1 Journal of Chemical Education
Gardiner H.Myers
