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There is no detectable change in the quantity of matter during an ordinary chemical reaction.

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  • Interesting facts about metals

    Metals have been used by people since ancient times. All the time the process of obtaining them was improved, useful alloys of various metals appeared. Let’s look at interesting facts about metals.

  • 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.

  • 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...

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A substance added to react with the charge, or a product of its reduction, in metallurgy, usually added to lower a melting point.


The concept in which two or more equivalent dot formulas for the same arrangement of atoms (resonance structures) are necessary to describe the bonding in a molecule or ion.

Carbonium ion

An orgainic ion carrying a positive charge on a carbon atom.

Dissociation Constant

Equilibrium constant that applies to the dissociation of a comples ion into a simple ion and coordinating species (ligands).

Native State

Refers to the occurrence of an element in an uncombined or free state in nature.



A chemical or compound that causes a sudden, almost instantaneous release or pressure, gas, heat and light when subjected to sudden shock, pressure, high temperature or applied potential.

Bond Order

Half the numbers of electrons in bonding orbitals minus half the number of electrons in antibonding orbitals. Bond order gives an indication to the stability of a bond. Also defined as the difference between the number of bonding electrons and antibonding electrons divided by two.


Different forms of the same element in the same physical state.

Total Ionic Equation

Equation for a chemical reaction written to show the predominant form of all species in aqueous solution or in contact with water.

Emission Spectrum

Spectrum associated with emission of electromagnetic radiation by atoms (or other species) resulting from electronic transitions from higher to lower energy states.