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This is a list of unsolved problems in chemistry. Problems in chemistry are considered unsolved when an expert in the field considers it unsolved or when several experts in the field disagree about a solution to a problem.
The interaction excites or ionizes the atoms, leading to an energy loss of the traveling particle. The non-relativistic version was found by Hans Bethe in 1930; the relativistic version (shown below) was found by him in 1932. [2] The most probable energy loss differs from the mean energy loss and is described by the Landau-Vavilov distribution. [3]
An example of the E1cB reaction mechanism in the degradation of a hemiketal under basic conditions. The E1cB elimination reaction is a type of elimination reaction which occurs under basic conditions, where the hydrogen to be removed is relatively acidic, while the leaving group (such as -OH or -OR) is a relatively poor one.
2,4-Dinitrophenol (2,4-DNP or simply DNP) is an organic compound with the formula HOC 6 H 3 (NO 2) 2. It has been used in explosives manufacturing and as a pesticide and herbicide. In humans, DNP causes dose-dependent mitochondrial uncoupling , causing the rapid loss of ATP as heat and leading to uncontrolled hyperthermia —up to 44 °C (111 ...
For example, sulfuric acid (H 2 SO 4) is a diprotic acid. Since only 0.5 mol of H 2 SO 4 are needed to neutralize 1 mol of OH −, the equivalence factor is: f eq (H 2 SO 4) = 0.5. If the concentration of a sulfuric acid solution is c(H 2 SO 4) = 1 mol/L, then its normality is 2 N. It can also be called a "2 normal" solution.
Half-life (symbol t ½) is the time required for a quantity (of substance) to reduce to half of its initial value.The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.
An alpha particle with a speed of 1.5×10 7 m/s within a nuclear diameter of approximately 10 −14 m will collide with the barrier more than 10 21 times per second. However, if the probability of escape at each collision is very small, the half-life of the radioisotope will be very long, since it is the time required for the total probability ...
[6] [8] For example, during heavy exercise, electrolytes are lost in sweat, particularly in the form of sodium and potassium. [8] The kidneys can also generate dilute urine to balance sodium levels. [8] These electrolytes must be replaced to keep the electrolyte concentrations of the body fluids constant.