-
First scientific element discovered by Henning Brand, phosphorus.
-
The German chemist Johann W. Dobereiner observed that there were groups of three elements that had very similar physical and chemical properties. Based on this I classify the elements into groups of three and call them triads.
-
The English Johann alexander Newlands ordered the known elements according to their atomic weights, in the eighth the chemical properties of the first were repeated. Newlands called this organization the law of octaves.
-
The chemists Ivanovich Dimitri Mendeleiev, and Lothar Meyer, published practically coincident periodic tables separately, in which the 63 elements known to that date were classified
-
Lord RayLeigh reported the discovery of a new gaseous element, called argon
-
William Ramsey, suggested that argon be placed between chlorine and potassium in a family with helium. Ramsey accurately predicted the future discovery of neon and its properties.
-
Henry G. J. Moseley suggested that the elements be arranged according to their increasing atomic number.
"The physical and chemical properties of the elements are a periodic function of their atomic numbers" -
The current periodic table or periodic system is based on the one proposed by D. Mendeleev in 1869. In it, the elements are ordered, from left to right, by increasing values of their atomic numbers (Z). In addition to this, the elements appear distributed in rows and columns.
