elements and the periodic table

The position of an element in the periodic table is generally determined by its electronic configuration e.g. electronic configuration of sodium is 2, 8, 1 i.e., it has three shells and one electron in the outermost shell. Hence, it is placed in period number..

Summary - The grouping of elements with similar properties together and the separation of elements with dissimilar properties is known as classification of elements. The table, which classifies elements on the basis of their properties, is called th..

The number of elements in these periods is based on the way electrons are filled into various shell..

Group IA, IIA and IIIA consists of metals of normal elements. They have 1, 2, or 3 valence electrons which they can easily donate to acquire the configuration of nearest noble gas. They become positively charged i.e., cations. ..

Later, Henry Gywn-Jeffreys Moseley showed that the atomic number of an element is numerically equal to the number of electrons round the nucleus. The number of electrons in turn is equal to the number of protons in the nucleus. He suggested that atomic number is a more fundamental proper..

Later, Henry Gywn-Jeffreys Moseley showed that the atomic number of an element is numerically equal to the number of electrons round the nucleus. The number of electrons in turn is equal to the number of protons in the nucleus. He suggested that atomic number is a more fundamental proper..

Group A 1A 2A 3A 4A 5A 6A 7A 0 Period 1 1 H 2 He Period 2 3 Li 2,1 4 Be 2,2 5 B 2,3 6 C 2,4 7 N 2,5 8 O 2,6 9 F 2,7 10 Ne 2,8 Period 3 11 Na 2,8,1 12 Mg 2,8,2 13 Al 2,8,3 14 Si 2,8,4 1..

Dobereiner's Triads - In the famous atomic theory of John Dalton (1805), it was suggested that the atoms of an element have a characteristic mass. So, attempts were made to classify elements on the basis of their atomic masses. In the year 1829, Johann Wolfgang Dobereiner, a Ger..

Cause of Periodicity of Elements - The modern periodic table is based on the electronic configuration of the elements. The properties of an element are determined largely by the electrons in its outermost or valence shell. Valence electron..

With the rapid development of Chemistry and the discovery of new elements, it was necessary to develop a simple way to study and remember the numerous properties of the elements and their compounds. This gave rise to the necessity of classification of the elements..