CHEMISTRY GLOSSARY

lithium    →   litij

Lithium was discovered by Johan August Arfvedson (Sweden) in 1817. The origin of the name comes from the Greek word lithos meaning stone, apparently because it was discovered from a mineral source whereas the other two elements, sodium and potassium, were discovered from plant sources. It is soft silvery-white metal. Lightest of metals. Reacts slowly with water and oxygen. Flammable. Can ignite in air. Reacts with water to give off a flammable gas. Lithium is obtained by passing electric charge through melted lithium chloride and from the silicate mineral called spodumene [LiAl(Si₂O₆)]. Used in batteries. Also for certain kinds of glass and ceramics. Some is used in lubricants.

manganese    →   mangan

Manganese was discovered by Johann Gahn (Sweden) in 1774. The origin of the name comes from the Latin word magnes meaning magnet, or magnesia nigri meaning black magnesia (MnO₂). It is hard, brittle, grey-white metal with a pinkish tinge. Impure forms are reactive. Rusts like iron in moist air. Manganese is most abundant ores are pyrolusite (MnO₂), psilomelane [(Ba,H₂O)₂Mn₅O₁₀] and rhodochrosite (MnCO₃). Pure metal produced by mixing MnO₂ with powered Al and ignited in a furnace. Used in steel, batteries and ceramics. The steel in railroad tracks can contain as much as 1.2 % manganese. It is crucial to the effectiveness of vitamin B₁.

Lennard-Jones potential    →   Lennard-Jonesov potencijal

The Lennard-Jones potential (or 12-6 potential) is a mathematically simple model that describes the interaction between two non-bonded and uncharged atoms (known as the van der Waals interaction). It was first proposed in 1924 by British physicist Sir John Edward Lennard-Jones (1894-1954). The Lennard-Jones Potential is given by the following equation

where V is the intermolecular potential between the two atoms or molecules, ε is the well depth and a measure of how strongly the two particles attract each other, σ is the distance at which the intermolecular potential between the two particles is zero, r is the distance of separation between centres of both particles.