Briefly outlines the theoretical basis of the phenomenon of photoconductivity and describes a simple experiment which demonstrates the photoconductive properties of cadmium sulfide. (JR)

Describes a number of activities designed to assist student understanding of the phenomenon of light bending when it passes from one meduim to another. (JR)

Describes two experiments in physics, using the same inexpensive apparatus, that may be performed as projects by high ability secondary science students. (JR)

Describes the laboratory procedures for the measurement of thermal expansion and viscosity of liquids. These experiments require inexpensive equipment and are suitable for secondary school physical science classes. (JR)

Introduces three demonstrations using rubber balloons: rate of reaction, air pressure, and solubility of gases in liquids. Provides the materials, procedure, questions, further investigation, and discussion in each demonstration. (YP)

Describes a technique for the supercooling of water, for use in the science classroom, involving adding common salt to a mixture of ice and water. Several investigations are included for use during (and after) the process of supercooling. (DS)

Describes the commercial applications of hydroponics, and then outlines ways in which this soilless plant culture method can be used in the science classroom and laboratory. Gives directions for making a suitable growth solution, and suggests appropriate student experiments involving hydroponics. (JR)

Presents a series of activities which focus on the study of the physical characteristics of water, including temperatures, opacity, pH-values, oxygen concentrations, reagents, and free CO2 concentrations. Indicates that ponds can provide the students with opportunities to learn chemistry, geology, biology, botany, and the effects of weather. (CC)

The use of 10cc. syringes in high school chemistry experiments can reduce the expense of equipment and lead to imaginative experimental designs. Describes the equipment and experimental procedures for four experiments utilizing syringes. (JR)

Describes some of the causes and consequences of particulate air pollution. Outlines the experimental procedures for measuring the amount of particulate materials that settles from the air and for observing the nature of particulate air pollution. (JR)

Describes two experiments using carbon dioxide cartridges to demonstrate Newton's third law of motion. (JR)

Light-emitting diodes (LEDs) are described and three classroom experiments are given, one to prove the, low power requirements and efficiency of LEDs, an LED on-off detector circuit, and the third an LED photoelectric smoke detector. (BB)