New World Encyclopedia integrates facts with values.
Written by online collaboration with certified experts.
Did you know?
The "Arthashastra" has been compared to Machiavelli's "The Prince" because of its brutal methods and unscrupulous ethics (read more)
Deuterium (chemical symbol D or ²H) is a stable isotope of hydrogen, found in extremely small amounts in nature. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen nucleus contains just one proton and no neutrons. Consequently, each atom of deuterium has roughly twice the mass of an ordinary hydrogen atom, and deuterium is also called heavy hydrogen. Water in which ordinary hydrogen atoms are replaced by deuterium atoms is known as heavy water.
Scientists have developed a variety of applications for deuterium and its compounds. For example, deuterium serves as a nonradioactive isotopic tracer to study chemical reactions and metabolic pathways. In addition, it is useful for the study of macromolecules by neutron scattering.
Popular Article: Biome
A biome, or "major life zone," is a large geographic region of the earth's surface with distinctive plant and animal communities. There are both terrestrial biomes, such as grasslands and tropical rain forests, and aquatic biomes, such as estuaries.
A biome may also be defined as an extensive ecosystem (ecological unit of living organisms and their abiotic environment) spread over a wide geographic area, or as a grouping of many ecosystems that share similar environmental features and communities (organisms living together in a certain area). Collectively, biomes comprise the biosphere, which is the thin area of the earth's surface where all organisms live.