Krypton - Chemistry Encyclopedia
Lanthanides - Chemistry Encyclopedia
The lanthanide or rare earth elements (atomic numbers 57 through 71) typically add electrons to the 4f orbitals as the atomic number increases, but lanthanum (4f0) is usually considered a lanthanide. Scandium and yttrium are also chemically similar to lanthanides.
Lanthanum - Chemistry Encyclopedia
Lawrencium - Chemistry Encyclopedia
Lead - Chemistry Encyclopedia
Lewis Structures - Chemistry Encyclopedia
In 1902, while trying to find a way to explain the Periodic Table to his students, the chemist Gilbert Newton Lewis discovered that the chemistry of the main-group elements could be explained using a model in which electrons arranged around atoms are conceived as occupying the faces of concentric cubes. This model was based on four assumptions.
Lipid Bilayers - Chemistry Encyclopedia
Lipid bilayers form the fundamental structures of cell membranes and thus provide a semipermeable interface between the interior and exterior of a cell and between compartments within the cell. Bilayer-forming lipids are amphipathic molecules (containing both hydrophilic and hydrophobic components).
Lipids - Chemistry Encyclopedia
Lipids are a class of biomolecules that is defined by their solubility in organic solvents, such as chloroform, and their relative insolubility in water. Interactions among lipids and of lipids with other biomolecules arise largely from their hydrophobic ("water-hating") nature.
Liquid Crystals - Chemistry Encyclopedia
In 1888 the Austrian botanist and chemist Friedrich Reinitzer, interested in the chemical function of cholesterol in plants, noticed that the cholesterol derivative cholesteryl benzoate had two distinct melting points. At 145.5°C (293.9°F) the solid compound melted to form a turbid fluid, and this fluid stayed turbid until 178.5°C (353.3°F), at which temperature the turbidity disappeared and the liquid became clear.
Liquids - Chemistry Encyclopedia
A liquid is one state in which matter can exist. A liquid can take the shape of any container it is placed in (unlike a solid), but the volume of the liquid will always remain constant (unlike a gas).
Lithium - Chemistry Encyclopedia
Low Density Lipoprotein (LDL) - Chemistry Encyclopedia
Lipids are nonpolar molecules and are relatively insoluble in aqueous solutions. At low concentrations, cholesterol and cholesterol esters, as well as other lipids, may form microscopic droplets called chylomicrons (lipid-protein complexes) that are somewhat stable in solution.
Lucretius - Chemistry Encyclopedia
Little is known about Titus Lucretius Carus beyond what can be gathered from his poem De rerum natura. He was born in about 95 B.C.E., but the exact date is uncertain.
Lutetium - Chemistry Encyclopedia
Magnesium - Chemistry Encyclopedia
Magnetism - Chemistry Encyclopedia
The magnetic properties of materials were recognized by the ancient Greeks, Romans, and Chinese, who were familiar with lodestone, an iron oxide mineral that attracts iron objects. Although the attractive or repulsive forces that act between magnetic materials are manifestations of magnetism familiar to everybody, the origin of magnetism lies in the atomic structure of matter.
Manganese - Chemistry Encyclopedia
Lavoisier, Antoine - Chemistry Encyclopedia
Antoine-Laurent Lavoisier, born in Paris, France, is considered the father of modern chemistry. During the course of his career, Lavoisier managed to transform just about every aspect of chemistry.
Lawrence, Ernest - Chemistry Encyclopedia
Ernest Orlando Lawrence was a pioneer of "big science," the use of complicated and expensive instrumentation by large teams of researchers.
Le Bel, Joseph-Achille - Chemistry Encyclopedia
French chemist Joseph-Achille Le Bel, who, with Jacobus van't Hoff, was the founder of modern stereochemistry.
Leblanc, Nicolas - Chemistry Encyclopedia
French chemist Nicolas Leblanc, inventor of the process for transforming sodium chloride (NaCL, or common salt) into soda ash.
Le Châtelier, Henri - Chemistry Encyclopedia
Henri-Louis Le Châtelier was born into a family of architects, engineers, and scientists in Paris. His family home was like a drop-in center for France's leading chemists.
Leclanché, Georges - Chemistry Encyclopedia
In 1866 Georges-Lionel Leclanché was granted French patent no. 71,865, which described a remarkable advancement in the technology of the primary electrochemical cell.
Leloir, Luis - Chemistry Encyclopedia
Luis Leloir was born in Paris in 1906. His parents were Argentine, and he resided in Buenos Aires from the age of two and for most of his career until his death in 1987.
Lewis, Gilbert N - Chemistry Encyclopedia
Gilbert Newton Lewis was born on October 25, 1875, in West Newton, Massachusetts. A precocious child, he received his early education at home and learned to read by the age of three.
Liebig, Justus von - Chemistry Encyclopedia
German chemist Justus von Liebig.
Lister, Joseph - Chemistry Encyclopedia
Joseph Lister is known as the founder of antiseptic surgery, a significant advance in medicine developed in the nineteenth century. Infection of wounds and surgical incisions was a major cause of hospital deaths before Lister developed a way of preventing these infections with chemical antiseptics.
Lonsdale, Kathleen - Chemistry Encyclopedia
English crystallographer Dame Kathleen Lonsdale, who established the molecular structure of benzene.