Sir William Knighton, Bart., 1776-1836

Chemical bonds are complex interactions between two or more atoms or ions, which reduce the potential energy of the molecule. Gilbert N. Lewis developed a model called the Lewis model that simplified the depiction of chemical bond formation and provided straightforward explanations for the chemical bonds seen in most common compounds.

Solubility equilibria are established when the dissolution and precipitation of a solute species occur at equal rates. These equilibria underlie many natural and technological processes, ranging from tooth decay to water purification. An understanding of the factors affecting compound solubility is, therefore, essential to the effective management of these processes. This section applies previously introduced equilibrium concepts and tools to systems involving dissolution and precipitation.
The...

Simpson’s Rule is a numerical integration method used to approximate the value of a definite integral when an exact antiderivative is difficult or impossible to obtain. The method estimates area by fitting a unique parabola through three equally spaced points on a curve and then integrating the resulting quadratic function over the interval. By using only a small number of sampled values, Simpson’s Rule provides an accurate approximation for many smoothly varying functions.A common practical...

Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...

Brick masonry uses bricks as the building blocks and involves building walls from individual bricks laid in mortar. The basic building block of brick masonry is the wythe, a vertical layer of bricks with a thickness of one brick. Within a wythe, bricks can be laid in various courses or patterns, with the most common being the stretcher course, where bricks are laid with their long edge horizontal and face parallel to the wall.
For thicker walls, multiple wythes are bonded together using...

A solute is a component of a solution that is typically present at a much lower concentration than the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
Concentrations may be quantitatively assessed using a wide variety of measurement units, each convenient for particular applications. Molarity (M) is a useful concentration unit for many applications in chemistry.