Provided is a model to depict how the development of process skills can be systematically achieved and in turn determine the students' achievement in science practicals. Modified laboratory instruction is compared with conventional laboratory instruction. The results of field testing on 164 ninth grade subjects are described. (MVL)

Water rockets are used to present Newton's three laws of motion to high school physics students. Described is an outdoor activity which uses four students per group. Provides a launch data sheet to record height, angle of elevation, amount of water used, and launch number. (MVL)

Presents an identification method which uses the process of elimination to identify pollination systems. Provides the polyclave key, methodology for using the key, a sample worksheet, and abbreviation codes for pollination systems. (MVL)

Examines the influence of enzyme and substrate concentrations, pH, temperature, and inhibitors on catalytic activity. Follows the influence of different phosphate concentrations in the growth medium on enzyme activity. Studies regulation of enzyme synthesis by repression. Includes methodology for six experiments. (MVL)

Offers several advantages over other possibilities as the enzyme of choice for a student's first exposure to a purification scheme. Uses equipment and materials normally found in biochemistry laboratories. Incorporates several important biochemical techniques including spectrophotometry, chromatography, centrifugation, and electrophoresis. (MVL)

Describes a project involving students in hands-on scientific experiment to locate and identify areas of water pollution, based on Delta Laboratories Adopt-A-Stream Program. Describes getting started, working cooperatively, community support, recording and using data. Includes data sheet, checklist, and photographs of students at study site. (TES)

Shows how video recordings of the Brownian motion of tiny particles may be made. Describes a classroom demonstration and cites a reported experiment designed to show the random nature of Brownian motion. Suggests a student experiment to discover the distance a tiny particle travels as a function of time. (MVL)

Offers challenging work at a higher level of technique than most students meet in elementary laboratory work. Uses a combined weight and volumetric sequence not shown in textbooks. Notes modern rapid balances help lower evaporation loss during weighings. Discusses the balance, weights, and buoyancy considerations. (MVL)

Notes that laboratory work should be more oriented towards puzzle solving rather than technique or illustration. Offers three organic laboratory puzzles which can be solved by melting point alone. Involves lab work at the 100-200-mg scale but still uses conventional glassware. (MVL)

Notes that this experiment takes safety and noncarcinogenic reactants into account. Demonstrates the use of diazonium salts for the replacement of an aromatic amine group by a phenolic hydroxyl. Involves two pleasant-smelling organic compounds, methyl anthranilate (grape) and methyl salicylate (oil of wintergreen). (MVL)

Discusses a three-week summer college honors course for talented high school juniors with three exams, lab six days a week, a research paper, field trips, and student panel discussions. Presents an overview of the course. Describes the lab which uses "E. coli" for DNA recombination. (MVL)

Describes the deterministic simulation (a given input always leads to the same output) and probabilistic simulation (new states are subject to predefined laws of chance). Provides examples of the application of the two simulations with mathematical expressions and PASCAL program. Lists seven references. (YP)

Follows the increase of the pH in a solution of vinegar during neutralization with commercial antacid tablets. Provided are background information, equipment details, procedures, and details of the data analysis. (MVL)

Models which demonstrate the concept of moment of force in two- and three-dimensional cases and have been well received by students are described. Photographs and instructions for each model are provided. (MVL)

Addresses whether or not science laboratory activities should become a thing of the past. Discusses the impact of the curriculum reforms of the 1960s and 1970s, physical restraints which cause teacher overload, rationale, and objectives of laboratory work. (RT)