Mendeleev calculated atomic number by increasing atomic number, which match the number of protons in an atomic nucleus of a single element
Mendeleev arranged elements in order of increasing mass. Later modern periodic table was discovered that contains elements arranged by atomic number.
Atomic mass. The modern table is based on atomic number.
Number of protons are taken. They are arranged by number of protons. Mendeleev arranged elements first according to atomic number
His table was sorted by atomic mass, not atomic number. (the way today's periodic table is sorted) Mendeleev was almost right, but they did not know about protons at the time. (atomic number is the number of protons in an element) There would have been absolutely no way of him figuring out they were related to atomic number if he didn't even know about atomic number
Mendeleev listed the atomic weights and chemical properties of elements as he began to organize them. He noticed that elements with similar properties appeared at regular intervals when arranged by increasing atomic weight.
The atomic number is equal to the number of protons in an atomic nucleus; the atomic number is the order number of a chemical element in the periodic table of Mendeleev.
Mendeleev arranged elements in order of increasing mass. Later modern periodic table was discovered that contains elements arranged by atomic number.
Mendeleev
Atomic number = Number of protons = Number of electrons (in the neutral state) Also the atomic number is number of a chemical element in the periodic table of Mendeleev.
Atomic mass. The modern table is based on atomic number.
Number of protons are taken. They are arranged by number of protons. Mendeleev arranged elements first according to atomic number
Atomic number was not used by Mendeleev to organize his periodic table. He organized the elements based on their atomic mass and properties, leaving gaps for undiscovered elements that were later filled.
Atomic number = number of protons = number of electrons (in the neutral state) Also the atomic number is the number of the position of a chemical element in the periodic table of Mendeleev.
Dmitri Mendeleev
The atomic number is the number of a chemical element in the periodic table of Mendeleev; the atomic number is equal to the number of protons and electrons. The atomic mass is the mass of an atom expressed in relative atomic mass units.
The numbers on Mendeleev's periodic table represent the atomic number of each element, which is the number of protons in the nucleus of an atom. This number determines the element's identity and its placement in the periodic table.
In 1913, almost fifty years after Mendeleev, Henry Moseley published the results of his measurements of the wavelengths of the X-ray spectral lines of a number of elements which showed that the ordering of the wavelengths of the X-ray emissions of the elements coincided with the ordering of the elements by atomic number. With the discovery of isotopes of the elements, it became apparent that atomic weight was not the significant player in the periodic law as Mendeleev, Meyers and others had proposed, but rather, the properties of the elements varied periodically with atomic number. When atoms were arranged according to increasing atomic number, the few problems with Mendeleev's periodic table had disappeared. Because of Moseley's work, the modern periodic table is based on the atomic numbers of the elements.