In a large-scale longitudinal study, 11-year-old schoolchildren were given a control-of-variables task, and their scores in this were related to their progress in learning about science at school over the next 3 years. The aim of the control-of-variables task was to measure children's understanding that in a properly controlled scientific…

The physiology of breath holding is complex, and voluntary breath-hold duration is affected by many factors, including practice, psychology, respiratory chemoreflexes, and lung stretch. In this activity, we outline a number of simple laboratory activities or classroom demonstrations that illustrate the complexity of the integrative physiology…

In this fourth and fifth grade activity, students become comfortable with the concept that light-years are a measure of distance, not time, and discover how we are looking back in time when we look at stars. Since the enormous distances in space can make astronomical studies even more confusing, students explore the meaning of a light-year by…

This paper presents an experimental activity based on the absorption of light colours by pigments. The activity is constructed using a stepwise design and offers an opportunity for students and teachers to compare and generalize the interactions between light and pigment colours. The light colours composing an artificial rainbow produced in the…

This inquiry-based experiment is designed for organic or biochemistry undergraduate students to deduce the identity of phospholipids extracted from chicken eggs and dietary supplements. This is achieved using thin-layer chromatography (TLC) data, a series of guided questions of increasing complexity, and provided relative retention factor (Rf)…

This chapter highlights the fit between youth-development-oriented programming and informal science activities in out-of-school time (OST) and illustrates how science and youth development can and should co-occur. The clover model and Dimensions of Success tool are introduced as lenses for designing and assessing science program quality in OST.…

This author wanted to begin her 10-grade biology course with an authentic inquiry that included a review of equipment use, investigation methods, and critical thinking skills. She also wanted to engage students in the practice of science while teaching biological core ideas and crosscutting concepts. She was at a loss as to what that inquiry might…

In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

Scale as a theme in science instruction is not a new idea. As early as the mid-1980s, scale was identified as an important component of a student's overall science literacy. However, the study of scale and the scale literacy of students in varying levels of education have received less attention than other science-literacy components. Foremost…

Science relies on standards for measurement. This article describes assessment of geometric shape, rather than size. The author considers the problem of establishing departure from roundness. In doing this he examines some curious geometric shapes, including non-circular shapes of constant width and shapes that rotate smoothly inside triangles.…

This "Science note" arose out of practical work involving the dilution of ethanoic acid, the measurement of the pH of the diluted solutions and calculation of the acid dissociation constant, K[subscript a], for each diluted solution. The students expected the calculated values of K[subscript a] to be constant but they found that the…

Shadows can be found easily everywhere around us, so that we rarely find it interesting to reflect on how they work. In order to raise curiosity among students on the optics of shadows, we can display the shadows in 3D, particularly using a stereoscopic set-up. In this paper we describe the optics of stereoscopic shadows using simple schematic…

It is a known fact that it takes a greater effort to run on an exercise treadmill when it is inclined with positive slope than when it is in a horizontal position. The reason seems simple: walking on an inclined treadmill is somehow equivalent to walking up a hill with the same inclination; when we walk up a hill, our own weight does negative work…

Gibbs energy profiles provide students with a visual representation of the energy changes that occur during enzyme catalysis, making such profiles useful as teaching and learning tools. Traditional kinetic topics, such as the effect of pH on enzyme activity, are often not discussed in terms of Gibbs energy profiles. Herein, the symbolism of Gibbs…

Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…