Many countries implement competitions in physics for high school students such as the national 'Physics Olympiads' that are often used to select students for participation in the International Physics Olympiad (IPhO), the Asian Physics Olympiad (APhO) or the Ibero-American Physics Olympiad (OIbF). Typically, in these competitions students are…

This paper describes a mini-project developed with 10th grade Portuguese students where, by using an experimental activity involving the use of natural dyes to colour wool, students acquired a better understanding of the concepts and relationship between the colour, the electromagnetic spectrum, and chemical bonding. As demonstrated by the results…

Leaves of higher terrestrial plants have small pores--stomata--responsible for gas exchange. The opening of each stoma results from the osmotic uptake of water by two specialised cells--the guard cells. Because of the involvement in this mechanism of ATPase-proton pumps and active transport of ions across membranes, we have designed an Exploring…