Scientific dictionary main page

Scientific dictionary

science park

Table of Elements

Chemical information

Science dictionary

scientific data

site map

Gift Shop


Index (A)

AA - AB

AC - AC

AD - AF

AG - AJ

AK - AM

AN - AN

AO - AR

AS - AV

AW - AZ

Moment of truth
More than 25 million people died in Europe from the bubonic plague (the black death) in five years, from 1347 to 1352.


A   B   C   D   E   F   G   H   I   J   K   L   M  
N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

back (AN-AN) AO - AR next page (AS-AV)

aphelion Astron.
The point at which an object, such as a planet or comet, orbiting the Sun which is farthest from the Sun.

apoapsis Astron.
The point at which an object orbiting a celestial body that is farthest from that body.

apogee Astron.
The point at which an object orbiting the Earth that is farthest from the Earth.

Apollo asteroid Astron.
An asteroid whose orbit intersects that of Earth. Named after asteroid 1862 Apollo. More precise definition for an Apollo asteroid is that its semi-major axis is larger than 1.0 AU and its perihelion distance is less than 1.017 AU.

apoptosis Biol.
See necrobiosis.

aqua regia Chem.
A mixture of acid made of one part concentrated nitric acid (HNO3) and three parts of concentrated hydrochloric acid (HCl), by volume. The individual acidic components when separated do not react with gold. However, in the presence of both nitrate and chloride ions, aqua regia can slowly dissolves gold.

dissolve gold with aqua regia

arc Math.
A segment along the circumference of a circle, a portion of a curve.

Archimedes's principle Phys.
A buoyancy principle which states that when a body is wholy or partly submerged in a liquid, it experiences an upthrust or buoyant force equals to the weight of the displaced quantity of liquid.

arene Chem.
Also known as aromatic hydrocarbon, an organic compound that contains at least one aromatic ring such as bezene, methylbenzene (toluene), naphthalene, etc.

arithmatic mean Math.
Of a given n numbers, which can be negative or positive, their sum divided by n:

arithmatic mean

back (AN-AN) AO - AR next page (AS-AV)

A   B   C   D   E   F   G   H   I   J   K   L   M  
N   O   P   Q   R   S   T   U   V   W   X   Y   Z  


| Copyright | Privacy | Disclaimer | Contact |

2004-2010 Etacude.com, all rights reserved.