Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive
 

Weighted average of the masses of the constituent isotopes of an element, The relative masses of atoms of different elements.

Latest Articles

  • Features of the Scanning Tunneling Microscope

    The scanning tunneling microscope (STM) invented by Heinrich Rohrer and Gerd Binnig in the 1980s still manages to do a great job today and competes with more advanced microscope types. The scanning tunneling microscope is used for studying the surface atoms that are found on various materials. The...

  • What are Compound Microscopes?

    Most of the microscopes used today are compound. A compound microscope features two or more lenses. A hollow cylinder called the tube connects the two lenses. The top lens, the one people look through, is called the eyepiece. The bottom lens is known as the objective lens. Below the two lenses is...

  • Use of diamonds

    Diamond is a crystalline modification of pure carbon formed in the deep interior of the Earth, in the upper mantle at depths of more than 80-100 kilometers, at exceptionally high pressure and temperature. It is the most precious stone, the hardest and most wear-resistant mineral, the most...

  • The most expensive metal in the world

    Do you think the most expensive metal is gold? No! On earth there are more valuable metals. But we need to divide the value of metals that occur in nature, and metals - isotopes, which are obtained in special laboratories. Let’s look at natural metals first.

  • Chemistry of the sky

    Chemistry can teach us about the composition of celestial bodies and determine their age.



Most Popular

Haber Process

A process for the catalyzed industrial production of ammonia from N2 and H2 at high temperature and pressure.

Structural Isomers

Compounds that contain the same number of the same kinds of atoms in different geometric arrangements.

Valence Shell Electron Pair Repulsion Theory

Assumes that electron pairs are arranged around the central element of a molecule or polyatomic ion so that there is maximum separation (and minimum repulsion) among regions of high electron density.

 

DP number

The degree of polymerization, the average number of monomer units per polymer unit.

Titration

A Procedure in which one solution is added to another solution until the chemical reaction between the two solutes is complete, the concentration of one solution is known and that of the other is unknown.

 

Semiconductor

A substance that does not conduct electricity at low temperatures but does so at higher temperatures.

Homologous Series

A series of compounds in which each member differs from the next by a specific number and kind of atoms.

Polymer

A large molecule consisting of chains or rings of linked monomer units, usually characterized by high melting and boiling points.

Primary Voltaic Cells

Voltaic cells that cannot be recharged, no further chemical reaction is possible once the reactants are consumed.

Oxidation Numbers

Arbitrary numbers that can be used as mechanical aids in writing formulas and balancing equations, for single- atom ions they correspond to the charge on the ion, more electronegative atoms are assigned negative oxidation numbers (also called Oxidation states).