Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...

All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they...

In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing...

Humans continually engage with an environment rich in potentially harmful chemicals. These are introduced to our bodies through inhalation, ingestion, or skin contact. These chemicals exist in various forms, such as air and environmental pollutants, agricultural chemicals, organic solvents, and heavy metals.
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...

Infectious diseases arise from intricate interactions between pathogens and their reservoirs. A reservoir of infection refers to the natural habitat where a pathogen lives, grows, and multiplies, serving as a continual source of infection. Reservoirs are broadly classified as either living or nonliving, and each plays a unique role in disease transmission, significantly influencing public health interventions and control strategies.Humans act as reservoirs for a wide array of pathogens,...

Cholera is an acute gastrointestinal disease caused by the Gram-negative bacterium Vibrio cholerae. It is transmitted primarily via the fecal-oral route through the ingestion of contaminated water or food.Vibrio cholerae is a motile, Gram-negative bacterium of the family Vibrionaceae, primarily associated with waterborne outbreaks in areas with inadequate sanitation. Although over 200 serogroups of V. cholerae exist, only O1 and O139 are responsible for epidemic cholera. The O1 serogroup,...