classification of groups of periodic table

In spite of the above advantages, Mendeleev's periodic table suffered defects as follows: The position of hydrogen was not correctly defined. It was placed in group I although it resembles both the group I elements - the alkali metals and the group..

Modern Periodic Table-Long Form Periodic Table of Elements - 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 numb..

In 1869, Mendeleev classified the then known 56 elements on the basis of their physical and chemical properties in the increasing order of the atomic masses, in the form of a table. Mendeleev had observed that properties of the elements orderly recur in a cyclic fashion. He found that th..

1.Chlorine is placed second after fluorine in group VIIA. 2. Other members of this group are fluorine, bromine, iodine and astatine (the last member is radioactive..

“Atomic Radius” is defined as the half the total distance between the two adjoining atoms. It increases when we go down the group (due to addition of new shells) and decreases along the period on moving from left to righ..

Covalent compounds are formed by the sharing of electrons by atoms of non-metallic elements between groups IVA and VIIA. The elements of these groups react with one another by sharing election pairs. Thus, the valency of an element in a covalent molecule is equal to the nu..

Position of Hydrogen in the Periodic Table - Hydrogen is the first element of the periodic table. Its atomic number is 1, which indicates the presence of only one electron in the atom of hydrogen. This electron is present in its first shell. Hydrogen resemble..

Hydrogen is the first element of the periodic table. Its atomic number is 1, which indicates the presence of only one electron in the atom of hydrogen. This electron is present in its first shell. Hydrogen resembles both alkali metals (group I A) as well as halogens (h..

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. ..

1.Chlorine is placed second after fluorine in group VIIA. 2. Other members of this group are fluorine, bromine, iodine and astatine (the last member is radioactive). 3. Members of this group are called 'halogens' meaning salt producers. 4. Atoms of halogen..