Charles Janet
Encyclopedia
Charles Janet was a French engineer, company director, inventor and biologist.
His studies of the morphology of the head of ants, wasps and bees, and his micrographs were of remarkable quality. He also worked on plant biology and finally wrote a series of papers on evolution. He was a prolific inventor and designed much of his own equipment, including a novel type of formicarium. In 1927 he turned his attention to the Periodic System of the elements and wrote a series of six articles in French, which were privately printed and never widely circulated. His only article in English was poorly edited and gave a confused idea of his thinking.
traced on the surfaces of four nested cylinders. By various geometrical transformations he derived several striking designs, one of which is his "left-step Periodic Table
", in which hydrogen
and helium
are placed above lithium
and beryllium
. It was only later that he realized that his arrangement concorded perfectly with quantum theory
and the electronic structure of the atom. He placed the actinides under the lanthanides twenty years before Glenn Seaborg, and he continued the series to element 120.
Janet's table differs from the standard table in placing the s-block elements on the right, so that the blocks of the periodic table are arranged in the natural order s, p, d, f from right to left. There is then no need to divide the table or move the f block into a 'footnote'. He believed that no elements heavier than no. 120 would be found, so he did not envisage a g block. In terms of atomic quantum numbers, each row corresponds to one value of the sum (n+l) where n is the principal quantum number
and l the azimuthal quantum number
. The table therefore corresponds to the Madelung rule, which states that atomic subshells are filled in order of increasing values of (n+l).
Janet also envisaged an 'element zero' - whose 'atom' would consist of two neutron
s, and he speculated that this would be the link to a mirror-image table of elements with negative atomic numbers - in effect anti-matter. He also conceived heavy hydrogen (deuterium). He died just before the discovery of the neutron, the positron and heavy hydrogen.
Life and work
Janet graduated from the Ecole des Mines and worked for some years in munitions. He then married the daughter of the owner of a manufacturing company and worked for it for the rest of his life, finding time for research in various branches of science. His collection of 40,000 fossils and other specimens was unfortunately dispersed after his death.His studies of the morphology of the head of ants, wasps and bees, and his micrographs were of remarkable quality. He also worked on plant biology and finally wrote a series of papers on evolution. He was a prolific inventor and designed much of his own equipment, including a novel type of formicarium. In 1927 he turned his attention to the Periodic System of the elements and wrote a series of six articles in French, which were privately printed and never widely circulated. His only article in English was poorly edited and gave a confused idea of his thinking.
Chemical ideas
Janet started from the fact that the series of chemical elements is a continuous sequence, which he represented as a helixHelix
A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...
traced on the surfaces of four nested cylinders. By various geometrical transformations he derived several striking designs, one of which is his "left-step Periodic Table
Periodic table
The periodic table of the chemical elements is a tabular display of the 118 known chemical elements organized by selected properties of their atomic structures. Elements are presented by increasing atomic number, the number of protons in an atom's atomic nucleus...
", in which hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
and helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
are placed above lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
and beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
. It was only later that he realized that his arrangement concorded perfectly with quantum theory
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
and the electronic structure of the atom. He placed the actinides under the lanthanides twenty years before Glenn Seaborg, and he continued the series to element 120.
Janet's table differs from the standard table in placing the s-block elements on the right, so that the blocks of the periodic table are arranged in the natural order s, p, d, f from right to left. There is then no need to divide the table or move the f block into a 'footnote'. He believed that no elements heavier than no. 120 would be found, so he did not envisage a g block. In terms of atomic quantum numbers, each row corresponds to one value of the sum (n+l) where n is the principal quantum number
Principal quantum number
In atomic physics, the principal quantum symbolized as n is the firstof a set of quantum numbers of an atomic orbital. The principal quantum number can only have positive integer values...
and l the azimuthal quantum number
Azimuthal quantum number
The azimuthal quantum number is a quantum number for an atomic orbital that determines its orbital angular momentum and describes the shape of the orbital...
. The table therefore corresponds to the Madelung rule, which states that atomic subshells are filled in order of increasing values of (n+l).
Janet also envisaged an 'element zero' - whose 'atom' would consist of two neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s, and he speculated that this would be the link to a mirror-image table of elements with negative atomic numbers - in effect anti-matter. He also conceived heavy hydrogen (deuterium). He died just before the discovery of the neutron, the positron and heavy hydrogen.