A simple inquiry-based activity called "Fruit Puzzle" was designed to investigate high school students' understanding of the relationship between the concepts of density and solution concentration at a submicroscopic level. The first activity allowed students to predict whether five types of fruit would sink or float in water and asked…

This activity allows students to visualize how to obtain different stoichiometries with various techniques in a single experiment. The involvement of three phases adds to the student's interest. Instructional materials are provided to facilitate the experimental procedures, interpretation of results, and error analysis. The reaction of Li from a…

The blue bottle experiment is a popular chemical demonstration because of its simplicity and visual appeal. Most papers on the topic focus on a new formulation or a new presentation, but only a few discuss pedagogical application for a full lab session. This article describes the use of this experiment in the first session of undergraduate…

Students often prefer to study animals rather than plants, because they see plants as passive, less interesting organisms. This paper proposes a simple hands-on laboratory exercise for high-school students (grade 12) to arouse their interest in learning about plants and to demonstrate to them that plants are active organisms capable of defending…

To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

A low-cost celestial globe is developed to support astronomical coordinate learning. It is used for demonstrating how stars are positioned and to analyse the motion of celestial bodies or diurnal motion. The model was implemented at a weekend astronomy camp provided for students from schools in the northeastern region of Thailand. A series of…

Bacterial conjugation is a genetic transfer that involves cell-to-cell between donor and recipient cells. With the current method used to teach students in genetic courses at the undergraduate level, the transconjugants are identified using bacterial physiology and/or antibiotic resistance. Using physiology, however, is difficult for both…