A-DNA and B-DNA are two secondary molecular conformations (among other allomorphs) that double-stranded DNA drawn into a fiber can assume, depending on the relative water content and other chemical parameters of the fiber. They were the first two forms to be observed by X-ray fiber diffraction in the early 1950s, respectively by Wilkins and…

To help teachers enrich their students' understanding of inquiry in Earth science, this article describes six modes of inquiry used by practicing geoscientists (Earth scientists). Each mode of inquiry is illustrated by using examples of seminal or pioneering research and provides pointers to investigations that enable students to experience these…

An in-class activity has been developed to assist students in discovering chromatographic separations. Designed on the basis of plate theory, the game has students use instructor-provided partition coefficients to establish equilibrium for two different items between a stationary and mobile phase. As students work through equilibration and mobile…

This experiment targets undergraduate students in an analytical or organic instructional context. Using a simple extraction, this protocol allows students to quantify and qualify monoterpenes in essential oils from citrus fruit peels. The procedures involve cooling down the peels by immersing them into icy water. After a few minutes, the chilled…

Recently, a high school Science Club generated a large number of questions involving temperature. Therefore, they decided to construct a thermal gradient apparatus in order to conduct a wide range of experiments beyond the standard "cookbook" labs. They felt that this apparatus could be especially useful in future ninth-grade biology classes, in…

Methods and optics of perceiving color in a black-and-white grating are described. A sample grating which produces the effect is included. (JN)

Suggested in this article are experiments that can be used in the classroom, are inexpensive, need simple equipment, and are easy for the children to conduct. (RB)

Science experiments that can be done at home are described and illustrated. (DB)

An experiment is conducted to measure the enthalpy of vaporization of volatile compounds like methylene chloride, carbon tetrachloride, and others by using gas chromatography. This physical property was measured using a very tiny quantity of sample revealing that it is possible to measure the enthalpies of two or more compounds at the same time.

A simple conductivity instrument in nonaqueous solvents is employed to project several features of the SN2 mechanism, which involves the Finkelstein reaction. The effects of the different variables of the SN2 mechanism are described.

The preparation of 7-hydroxy-3-carboxycoumarin starting from 2,4-dihydroxybenzaldehyde, and malonitrile, by one-pot consecutive reactions, carried out in water under heterogenous conditions is presented. The experiment encourages students to think in terms of reaction mechanisms.

The purpose of this research was to determine how metal oxide used in a thermite reaction can impact the production of nanoparticles. The results showed the presence of nanoparticles (less than 1 micron in diameter) of at least one type produced by each metal oxide. The typical particles were metallic spheres, which ranged from 300 nanometers in…

The experiment to measure concentration of Photophysical Characterization(BHT) and determine percent recovery in chewing gum is described. The results demonstrated that over time, the concentration of BHT in the extract decreased owing to aerial oxidation.

We present an identification key to the common rodent prey found in owl pellets from the Northwestern (NW) and Southeastern (SE) United States that is based on differences in incisor size (arc diameter) among genera.