atomic number

The number of atoms, which constitute one molecule of an element, is called its atomicity. Phosphorus: P 4 - 4 atomicity Sulphur: S 8 - 8 atomicity Oxygen: O 2 - 2 atomicity Recently a different form of carbon - C 6 0 has been discovered. ..

Experimentally it is determined that the mass of an atom is very small ranging from 1.7 x 10 - 2 4 g to about 4.0 x 10 - 2 2 g. These small masses are terribly impractical to work with. Thus, it became necessary to reduce the atomic masses into simple figures. Hydrogen being the..

The existence of negative and positive charges on these materials can be explained on the basis of the structure of the atom. Almost all the mass of an atom resides in a central nucleus which contains a number of tightly packed protons and neutrons. As the protons are ..

The atomic and ionic radii of group 15 elements are smaller than the atomic radii of the corresponding group 14 elements. This is because of increased nuclear charge. On going down the group, the atomic radii increase due to the increase in number of shells...

Atomic Orbital Molecular Orbital An electron in atomic orbital is under the influence of only one positive nucleus of the atom An electron in molecular orbital is under the influence of two or more nuclei depending upon the number of atomsh..

The atomic and ionic radii of the elements of this group increase on going down the group. This is due to the increase in the number of electron shell..

Atom Ion An atom is a neutral particle [number of e - = number of p + ] An ion is a charged particle [number of e - ≠ number of p + ] An atom is unstable. An ion is stable. An atom is incap..

Being the first elements of each period, alkali metals have the largest atomic and ionic radii in their respective periods. As we move within a period, the atomic radius and ionic radius tend to decrease due to increase in the effective nuclear charge. On moving down the group,..

John Dalton provided a simple theory of matter to provide theoretical justification to the laws of chemical combinations in 1805. The basic postulates of the theory are: All substances are made up of tiny, indivisible particles called atoms. Atoms of the same element are identic..

An atomic orbital is the space around the nucleus in which the probability of finding the electron is maximum. These most probable regions can be diagrammatically represented by cloud density (dot) diagrams. The density of dots (or lack of them) in any region of the cloud diagram, indicat..