This study was conducted to examine the results of using a low-cost hands-on setup in combination with accompanying activities to promote understanding of the contact mode of atomic force microscopy (AFM). This contact mode setup enabled learners to study how AFM works by hand scanning using probing cantilevers with different characteristics on…

Hairy root transformation has been widely adapted in plant laboratories to rapidly generate transgenic roots for biochemical and molecular analysis. We present hairy root transformations as a versatile and adaptable model system for a wide variety of undergraduate laboratory courses and research. This technique is easy, efficient, and fast making…

A simple experiment to reveal the dimension of the pore space in sponges is proposed. This experiment is suitable for the first year of a physics or engineering course. The calculated dimension of the void space in a sponge of density 16 mg cm[superscript -3] was 2.948 [plus or minus] 0.008. (Contains 2 figures.)

Using macroscopic thermodynamics, the general law for adiabatic processes carried out by an ideal gas was studied. It was shown that the process reversibility is characterized by the adiabatic reversibility coefficient r, in the range 0 [less than or equal] r [less than or equal] 1 for expansions and r [greater than or equal] 1 for compressions.…

The problem of obtaining the apparent equation of motion and shape of a moving body from its arbitrary given equation of motion in special relativity is considered. Also the inverse problem of obtaining the body's equation of motion from a known equation of motion of its image is discussed. Some examples of this problem solution are considered. As…

Two compounds, K[subscript 2][Cu(C[subscript 2]O[subscript 4])[subscript 2]] times 4H[subscript 2]O, 1, and K[subscript 2][Cu(C[subscript 2]O[subscript 4])[subscript 2]] times 2H[subscript 2]O, 2, were synthesized under controlled conditions. By controlling the concentration of the reaction solutions, it is possible to isolate a kinetic product 1…

The Millikan oil drop experiment has been characterized as one of the "most beautiful" physics experiments of all time and, certainly, as one of the most frustrating of all the exercises in the undergraduate physics laboratory. A literature review reveals that work done on addressing student difficulties in performing the oil drop experiment has,…

A unique, interdisciplinary collaboration between chemistry and classics has led to the development of an experiment for nonscience majors. This instrumental analysis experiment was designed for use in an archaeology course to quantify the amount of lead in ancient bronze coins. The coins were corroded beyond visual identification, so provenance…

A discovery-based nucleophilic substitution experiment is described in which students compare the reactivity of chloride and iodide ions in an S[subscript N]2 reaction. This experiment improves upon the well-known "Competing Nucleophiles" experiment in that it does not involve the generation of hydrogen halide gas. The experiment also introduces…

A single-pot procedure for the preparation of methyl salicylate (oil of wintergreen) from commercial aspirin tablets has been developed. The synthesis proceeds via a tandem transesterification-Fischer esterification using acidic methanol and can be carried out using either conventional or microwave heating. The experiment helps demonstrate acyl…

The aim of this study was to evaluate the effects of living animals on pupils' intrinsic motivation and knowledge. Various studies from the late 1970s and 1980s stress the high effectiveness of authentic learning experiences in pupils' knowledge acquisition. However, there are only few current empirical studies on this topic. The research question…

This integrative, cross-curricular lab engages middle school biology students in an exercise involving ecology, arthropod biology, and mathematics. Students research the anatomy and behavioral patterns of a species of brine shrimp, compare the anatomy of adult and juvenile brine shrimp, and graph and interpret results. In this article, the authors…

A new procedure using a student-friendly least-squares multiple linear-regression technique utilizing a function within Microsoft Excel is described that enables students to calculate molecular constants from the vibronic spectrum of iodine. This method is advantageous pedagogically as it calculates molecular constants for ground and excited…

The dissociation constant, K[subscript d], of the binding of riboflavin-binding protein (RP) with neutral red (NR) can be determined by titrating RP to a fixed concentration of NR. Upon adding RP to the NR solution, the maximum absorption peak of NR shifts to 545 nm from 450 nm for the free NR. The change of the absorption can be used to determine…

The speed of light is an essential topic in the teaching of physics at school and at university, either with respect to the type of experiment or of course with respect to its genuine inherent importance. In reality, the various available experiments are hardly ever performed in class for many reasons. Therefore, we offer this experiment as a…