Discusses the missing water on Mars. Describes five experiments simulating conditions on Mars: (1) behavior of dry ice; (2) low-pressure vacuum; (3) freezing point depression; (4) water in hydrated minerals and clay; and (5) properties of carbon dioxide. (YP)

Provides background information for teachers on the chemistry of flourine. Points out that it links aerosols with refrigerants, anaesthetics with fire-fighting agents, batteries with blood substitutes, and atomic energy with the steel, petroleum, and aluminum industries. (JN)

Develops a teaching scheme for 11-13 year-olds based on different types of investigational practical work. Includes discussion of difficulties in investigations, four types of investigations, and deployment in the curriculum. (YP)

Addresses the principles and problems associated with the use of significant figures. Explains uncertainty, the meaning of significant figures, the Simple Rule, the Three Rule, and the 1-5 Rule. Also provides examples of the Rules. (ML)

Provides background information for teachers on the nature and production of antibodies. Points out that the production of monoclonal antibodies blends the malignant with the beneficial to create a medical tool of exciting potential. (JN)

Provides a method for correcting the photoemission from a collector when using the photoelectric effect experiment to determine Planck's constant. The problem results from a negative current through the cell and makes the measurement of the cutoff potential difficult. (DH)

This section of the journal includes several short notes on science activities and materials for secondary schools. Activities and materials are included that relate to biology, microbiology, microcomputers, chemistry, and physics. (RH)

Presents information on the moment of inertia of a tennis racket about its principal axes. This information (not available from conventional sources) is useful since it influences how the racket plays and how the racket feels when it is swung. In addition, measurements of motion can be easily made by undergraduate students. (JN)

Presents a nonmathematical approach to help students understand that there are two types of coherence and to associate coherence as a property of the illumination at an object itself. The approach also lends itself to an introduction to the Fourier approach for analyzing imaging systems. (JN)

Surveys careers in working with animals and gives suggestions for use of this topic in the classroom. Activities involve identifying reasons for choosing any career, careers involving animals (traditional and nontraditional), community personnel, and pros and cons of animal careers. Two student activity sheets are included for duplicating. (DH)

Described is the teaching of technology in British secondary schools. Some of the types of technology courses are described and issues and trends related to the teaching of technology are considered. (RH)

Discusses the development of the concept of atomicity and some of the many which can be used to establish its validity. Chemical evidence, evidence from crystals, Faraday's law of electrolysis, and Avogadro's number are among the areas which show how the concept originally developed from a purely philosophical idea. (JN)

Materials as ordinary as glacial till often afford instructive resources for classroom demonstration, field study, and laboratory analysis, rewarding the investigator with information about provenance, glacial transport history, environment and mode of deposition, and possible postglacial diagenesis. (Author)

Reviews the basic properties and evidence for their existence. (The sequel will consider the consequences if a human being had opportunity to interact directly with a black hole.) (JN)

Indicates that periodic table users will see changes in group notation as publishers and authors adopt revisions that already have been made or are being made. The revisions seek to remove ambiguities that have existed in that notation. A sample table is included which shows both old and new notations. (JN)