Seaweed is rich in iodine, an essential component for the formation of thyroid hormones. Iodine deficiency is still a problem in the 21st century despite iodination programmes. Without sufficient iodine in the diet, we risk a decline in brain development and growth in fetuses and children. This key micronutrient is essential for the formation for…

Nitrogen gas dominates the Earth's atmosphere but is largely ignored. Molecular nitrogen is extremely stable and so nitrogen is termed inert. What would happen if another 'inert' gas were the dominant species instead of molecular nitrogen? Here we show how unique nitrogen is and how important it has been to life on planet Earth.

An introduction to the noble gases and chemical bonding via Lewis theory and the octet rule are common inclusions in secondary school curricula. However, the usual approach may lead to misconceptions and difficulties when valence bond (VB) theory and valence shell electron pair repulsion (VSEPR) theory are taught at a later pre-university stage.…

This article argues that we need to make use of our everyday experiences when introducing concepts in chemistry that are often obscure. It uses reaction rates as an example and explores a common misconception related to the explanation of the effect of rising temperature on the rate of slow reactions.

Contrary to current IUPAC recommendations, the chemical element X should be defined as the nucleus of the X atom. Consequently, different isotopes with their different nuclei belong to different elements, each one with its own physical and chemical properties. This view leads to the conclusion that we no longer have a periodic table of the…

There has been widespread interest in the study of oxoacids of phosphorus owing to their characteristic structures and uses in various areas of daily life. In this article, a new strategy is recommended to determine their structures. This strategy will help to develop problem-solving skills and creativity among students. The strategy is based on…

Traditionally we consider infection to arise from viruses, bacteria and parasites. Prions are infectious proteins without any nucleic acids, and therefore do not represent living things. Despite this, they have the ability to replicate themselves and cause diseases such as mad cow disease (bovine spongiform encepthalopathy) and human…

Activation energies form an energy barrier to a chemical reaction taking place. Simple collision theory, i.e. that particles need to collide to react, would suggest that activation energy is the energy needed to overcome a coulombic barrier provided by the negatively charged electrons contained within energy shells surrounding an atomic nucleus.…

Students often struggle to determine whether changes in matter are physical or chemical; for example, they may have difficulty labelling a candle melting as a physical change but a candle burning as chemical change. Here we describe a lesson that we used to integrate conceptual learning about physical and chemical changes using the…

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…

Matter can be described and explained in a number of ways, using models of increasing complexity depending on the intended audience. Under the current National Curriculum for England, the kinetic theory of matter is taught to 11- and 12-year-olds in secondary schools to explain the structure of solids, liquids and gases and their behaviour when…

Astro Academy: Principia is an education programme developed by the UK National Space Academy for the UK Space Agency (UKSA) and the European Space Agency (ESA). The Academy designed, constructed, flight-qualified and developed experimental procedures for a suite of physics and chemistry demonstration experiments that were conducted by ESA…