A BASIC computer program was written for an experiment that measures the time of a fall of a ball-bearing dropped through a measured distance. However, the timing subroutine was written in machine language. The reason for using machine language, the machine language program, hardware used, and the experiment are discussed. (JN)

Describes: (1) a microcomputer demonstration of autocatalysis; (2) a safe alternative to ethanol and methanol; (3) a simple condenser for test-tube reactions; (4) a new procedure for studying the magnetic properties of transition metal compounds; (5) plasticization of the polymer PVC; and (6) some thoughts on polybasic acids and their salts. (JN)

Describes: the chemical history of a pencil; a simple solar camera for measuring the sun's diameter; the experimental comparison of the thermal stability of metal carbonates; and the introduction of the concept of weight as a force to young children. A computer program listing on color mixing is also provided. (JN)