Who Invented The Periodic Table
Who invented the periodic table?
Dmitri Mendeleev invented the periodic in 1869, 5 years after John Newlands put forward his law of Octaves.
Part of Dmitri’s periodic table
He realised that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table. He also stated:
The elements, if arranged according to their atomic mass, exhibit an apparent periodicity of properties.
Elements which are similar as regards to their chemical properties have atomic weights which are either of nearly the same value (e.g., Pt, Ir, Os) or which increase regularly (e.g., K, Rb, Cs).
The arrangement of the elements, or of groups of elements in the order of their atomic masses, corresponds to their so-called valencies, as well as, to some extent, to their distinctive chemical properties; as is apparent among other series in that of Li, Be, B, C, N, O, and F.
The elements which are the most widely diffused have small atomic weights.
The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound body.
We must expect the discovery of many yet unknown elements – for example, elements analogous to aluminium and silicon – whose atomic weight would be between 65 and 75.
The atomic weight of an element may sometimes be amended by a knowledge of those of its contiguous elements. Thus the atomic weight of tellurium must lie between 123 and 126, and cannot be 128.
Certain characteristic properties of elements can be foretold from their atomic masses.
In 1945 Glenn Seaborg identified lanthanides and actinides (atomic number >92), which are usually placed below the periodic table.
In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discovered radium and polonium. They discovered that beta particles were negatively charged.
In 1894 William Ramsay and Lord Rayleigh discovered the “noble gases” which were added to the periodic table in group 0.
In the physical sciences, subatomic particles are particles much smaller than atoms. There are two types of subatomic particles: elementary particles, which according to current theories are not made of other particles; and composite particles
The mass number of an atom is the total number of protons and neutrons it contains
The atomic number of an atom is the number of protons it contains
https://www.google.co.uk/webhp?sourceid=chrome-instant&rlz=1C1GGGE_en-gbGB611GB611&ion=1&espv=2&ie=UTF-8#q=subatomic+particles
Dmitri Mendeleev invented the periodic in 1869, 5 years after John Newlands put forward his law of Octaves.
Part of Dmitri’s periodic table
He realised that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table. He also stated:
The elements, if arranged according to their atomic mass, exhibit an apparent periodicity of properties.
Elements which are similar as regards to their chemical properties have atomic weights which are either of nearly the same value (e.g., Pt, Ir, Os) or which increase regularly (e.g., K, Rb, Cs).
The arrangement of the elements, or of groups of elements in the order of their atomic masses, corresponds to their so-called valencies, as well as, to some extent, to their distinctive chemical properties; as is apparent among other series in that of Li, Be, B, C, N, O, and F.
The elements which are the most widely diffused have small atomic weights.
The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound body.
We must expect the discovery of many yet unknown elements – for example, elements analogous to aluminium and silicon – whose atomic weight would be between 65 and 75.
The atomic weight of an element may sometimes be amended by a knowledge of those of its contiguous elements. Thus the atomic weight of tellurium must lie between 123 and 126, and cannot be 128.
Certain characteristic properties of elements can be foretold from their atomic masses.
In 1945 Glenn Seaborg identified lanthanides and actinides (atomic number >92), which are usually placed below the periodic table.
In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discovered radium and polonium. They discovered that beta particles were negatively charged.
In 1894 William Ramsay and Lord Rayleigh discovered the “noble gases” which were added to the periodic table in group 0.
In the physical sciences, subatomic particles are particles much smaller than atoms. There are two types of subatomic particles: elementary particles, which according to current theories are not made of other particles; and composite particles
The mass number of an atom is the total number of protons and neutrons it contains
The atomic number of an atom is the number of protons it contains
https://www.google.co.uk/webhp?sourceid=chrome-instant&rlz=1C1GGGE_en-gbGB611GB611&ion=1&espv=2&ie=UTF-8#q=subatomic+particles