This laboratory experiment consists of the synthesis of two series of alkaline-earth titanates (calcium-strontium and strontium-barium)to corroborate Vegard's law by obtaining their X-ray diffraction patterns and plotting the lattice parameter versus mole fraction of both cations. This experiment allows students to understand the key concepts in…

Atoms may repel or attract each other, but bound systems get virtually all of the attention in the classroom. To address the imbalance, instructors can explore the basis of repulsion in a few simple systems and highlight the important role played by the Pauli principle. A good example is the first triplet excited state of H[subscript 2] wherein…

Is the reductionist approach to teaching chemical principles in the laboratory adequate for students to make effective evaluations? In this work, using the example of sunscreens, students first assessed the analytical chemistry parameters of the active ingredients, later comparing and contrasting them with organic chemistry information for…

Thomas Graham discovered the law that bears his name while studying gas diffusion into air and other gases. He also found that the same relationship held with gas effusion, the movement of gases through a pinhole into a vacuum. Modern understanding of diffusion and effusion is based on kinetic-molecular theory, and it is generally accepted that…

A research-based inorganic chemistry laboratory course is described. Using the defined protocol of a course-based undergraduate research experience (CURE), students undertake a self-designed research project to identify new catalysts for the dehydrogenation of ammonia borane. Students select ligands and metals, prepare and characterize catalysts…

This article aims to introduce the lanthanides (also known as the lanthanoids) to teachers and their students. The lanthanides are not mere "footnotes" at the bottom of the periodic table but make up a group of interesting and unique metallic elements. They and their compounds have widespread technological applications that have become…

The use of [superscript 1]H NMR spectroscopy to analyze the number-average molecular weight of a methoxy poly(ethylene glycol) (MPEG) and an acetate derivative of this MPEG is described. These analyses illustrate NMR principles associated with the chemical shift differences of protons in different environments, NMR integration, and the effect of…

Small organic molecules offer a rich opportunity to discuss the interplay of chemical structure with properties such as the melting point and phenomena such as glass formation and can form the basis of fundamental considerations of structure-property relationships in macromolecules. Of particular importance are thermal transitions, specifically…

The Australian Curriculum (n.d.) describes chemistry as having three interrelated strands, Science Inquiry Skills, Science as a Human Endeavour and Science Understanding. It also states "... the three strands of the Australian Curriculum: Science should be taught in an integrated way". This article will explore a model for integrating…

The radioactive nature of technetium is discussed using a combination of introductory nuclear physics concepts and empirical trends observed in the chart of the nuclides and the periodic table of the elements. Trends such as the enhanced stability of nucleon pairs, magic numbers, and Mattauch's rule are described. The concepts of nuclear binding…

The ability of certain organometallic reagents to react via 1,2- or 1,4-addition to an a,ß-unsaturated ketone is a fundamental example of regioselectivity at the second-year undergraduate organic level. The following two experiments were designed to demonstrate this preference by exploiting carvone as an inexpensive chiral, nonracemic substrate.…

The molecular structure of living organisms and the complex interactions amongst its components are the basis for the diversity observed at the macroscopic level. Proteins and nucleic acids are some of the major molecular components, and play a key role in several biological functions, such as those of development and evolution. This article…

Research in organic chemistry education has revealed that students often rely on rote memorization when learning mechanisms. Not much is known about student productive resources for causal reasoning. To investigate incipient stages of student causal reasoning about single mechanistic steps of organic reactions, we developed a theoretical framework…

British scientist John Dalton (1766-1844), French scientist Joseph Louis Gay-Lussac (1778-1850), and Italian scientist Amedeo Avogadro (1776-1856) are familiar to many chemistry students. Such students may understand the importance of Dalton's atomic theory, model how Gay-Lussac's law relates the pressure and the temperature of a gas, and use…

Only diazotrophic bacteria, called "Rizhobia," living as symbionts in the root nodules of leguminous plants and certain free-living prokaryotic cells can fix atmospheric N[subscript 2]. In these microorganisms, nitrogen fixation is carried out by the nitrogenase protein complex. However, the reduction of nitrogen to ammonia has an…