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black humor

(Encyclopedia)black humor, in literature, drama, and film, grotesque or morbid humor used to express the absurdity, insensitivity, paradox, and cruelty of the modern world. Ordinary characters or situations are usu...

electronegativity

(Encyclopedia)electronegativity ĭlĕkˌtrōnĕgətĭvˈətē [key], in chemistry, tendency for an atom to attract a pair of electrons that it shares with another atom (see chemical bond). For example, the molecule...

Solvay process

(Encyclopedia)Solvay process [for Ernest Solvay], commercial process for the manufacture of sodium carbonate (washing soda). Ammonia and carbon dioxide are passed into a saturated sodium chloride solution to form s...

fuel cell

(Encyclopedia)fuel cell, electric cell in which the chemical energy from the oxidation of a gas fuel is converted directly to electrical energy in a continuous process (see oxidation and reduction). The efficiency ...

radiation weapon

(Encyclopedia)radiation weapon or radiological weapon, a bomb or warhead that uses conventional chemical explosives to disperse radioactive material, sometimes called a “dirty bomb.” Designed to produce radiati...

pH

(Encyclopedia)pH, range of numbers expressing the relative acidity or alkalinity of a solution. In general, pH values range from 0 to 14. The pH of a neutral solution, i.e., one which is neither acidic nor alkaline...

Groves, Leslie Richard

(Encyclopedia)Groves, Leslie Richard, 1896–1970, American army officer and engineer who headed the program that developed America's atomic bomb, b. Albany, N.Y., grad. West Point (1918). He was commissioned in th...

molecule

(Encyclopedia)molecule mŏlˈəkyo͞ol [key] [New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, a...

formula weight

(Encyclopedia)formula weight, in chemistry, a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a formula by the number of atoms of that element present in the formula, an...

dissociation

(Encyclopedia)dissociation, in chemistry, separation of a substance into atoms or ions. Thermal dissociation occurs at high temperatures. For example, hydrogen molecules (H2) dissociate into atoms (H) at very high ...