development elements grouped

In some cases Mendeleev placed elements according to their similarities in properties and not in increasing order of their atomic masses, while some dissimilar elements were grouped together. Thus, the position of these elements was not justified. For exampl..

Grouping of Elements - In the long form of the periodic table, elements are grouped into four main blocks, purely on the basis of electronic configurations. Elements are grouped in blocks 's', 'p', 'd' and 'f' depending on the nature of or..

An element is defined as a pure substance as it is made up of only one kind of atoms having the same atomic number. The smallest particle of an element is the atom, which has all the properties of that element. It cannot be further reduced to simpler substances by ord..

"An element is a pure substance which is made up of only one kind of atoms having the same atomic number." "The smallest particle of an element is the atom which, has all the properties of that element." "An element cannot be broke..

Representative or Main Group Elements - These consist of all 's' and 'p' block elements excluding the noble gases (group 18 elements). The chemical properties of the representative elements are determined by the number of valence electrons..

These consist of all 's' and 'p' block elements excluding the noble gases (group 18 elements). The chemical properties of the representative elements are determined by the number of valence electrons in their atom..

. These cells are called sporogenous cells . These sporogenous cells undergo a few mitotic divisions to increase their number and form the microspore mother cells or microsporocytes . The microsporocytes are diploid and usually closely packed. Each diploid microsporocyte undergoes meiosis, giving r..

Physical Characteristics of Group 15 Elements - The important physical constants of group 15 elements are given bel..

The important physical constants of group 15 elements are given bel..

Physical Characteristics of Group 13 Elements - The important physical constants of group 13 elements arc given in table and their physical characteristics are discussed bel..