Measurement of the level of a liquid is needed in many hydrodynamic situations. In the present article, this has been achieved with a conductivity sensor for the specific case of water levels. The use of this system is illustrated by the automation of a gasometer in which the gas is collected in an inverted measuring cylinder resting in a water…

In this experiment the over-the-counter pain reliever ibuprofen is resolved using (S)-(-)-[alpha]-phenethylamine as the resolving agent. This procedure has several key advantages over previous resolution experiments. First, it involves the resolution of a well-known medicinal compound of commercial importance. Second, the resolution process is…

A device that can demonstrate equilibrium, kinetic, and thermodynamic concepts is described. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when the leaf blower is turned on and various air pressures are…

The determination of sulfate concentration in water by indirect EDTA titration is an instructive experiment that is easily implemented in an analytical chemistry laboratory course. A water sample is treated with excess barium chloride to precipitate sulfate ions as BaSO[subscript 4](s). The unprecipitated barium ions are then titrated with EDTA.…

Using the traditional serological tests and the most novel techniques for DNA fingerprinting, forensic scientists scan different traits that vary from person to person and use the data to include or exclude suspects based on matching with the evidence obtained in a criminal case. Although the forensic application of these methods is well known,…

In this article, we describe an inexpensive, two-session undergraduate laboratory activity that introduces important molecular biology methods in the context of biodiversity. In the first session, students bring tentatively identified flies (order Diptera, true flies) to the laboratory, extract DNA, and amplify a region of the mitochondrial gene…

The science and technology of radio receives little attention in contemporary education. This article discusses ways to explore the basic operating principles of radio. (Contains 4 figures, 3 footnotes, and 2 notes.)

This is the story of how a typical middle school lab was transformed into an open-ended inquiry experience through a few small, but very powerful, changes. By allowing students to follow their own questions, the classroom filled with enthusiasm and students learned much more about photosynthesis, respiration, and the scientific processes. The…

Previous research (e.g., S. A. Gelman & E. M. Markman, 1986; A. Gopnik & D. M. Sobel, 2000) suggests that children can use category labels to make inductive inferences about nonobvious causal properties of objects. However, such inductive generalizations can fail to predict objects' causal properties when (a) the property being projected varies…

The purpose of this research is to construct a conceptual framework for use in capturing students' unstable perception regarding the establishment of the universality of propositions through experimentation/measurement in school geometry. As a conceptual framework, this research uses a quadrangular-pyramid model comprised of five representative…

Methylphenidate treatment is used for Attention Deficit Hyperactivity Disorder and can improve learning and memory. Previously, improvements were considered a by-product of increased attention; however, we hypothesize that methylphenidate directly alters mechanisms underlying learning and memory, and therefore examined its effects on hippocampal…

When given the opportunity to take notes in memory tasks, children sometimes make notes that are not useful. The current study examined the role that task constraints might play in the production of nonmnemonic notes. In Experiment 1, children played one easy and one difficult memory game twice, once with the opportunity to make notes and once…

Children learn about properties of materials as they walk through a fabric store, help in the kitchen, or dig in the garden. Directed explorations in the classroom build on these early experiences. In the inquiry-based activity described here, students prepare to learn about wet and dry ingredients (liquids and solids) and how they mix together by…

The attention network test (ANT) is a brief computerized battery measuring three independent behavioral components of attention: Conflict resolution (ability to overcome distracting stimuli), spatial Orienting (the benefit of valid spatial pre-cues), and Alerting (the benefit of temporal pre-cues). Imaging, clinical, and behavioral evidence…

For several years, the author's fifth-grade students raised and observed plants, kept journals, and analyzed the functions of the parts of a plant. But this year, a near disaster taught her a lesson and increased the value of the activity for her students. Not only did students learn about plants, they now understand what a variable is and how…