atomic number

Atomic Mass of Elements - 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 int..

Atomic Structure and Charges - 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 ..

The scale in which the relative atomic masses of different atoms are expressed is called atomic mass unit scale. Atomic masses are not expressed as whole numbers because natural elements are mixtures of two or more isotopes. The atomic ..

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 neutron..

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..

It is very difficult to accurately weigh the number of atoms as they are extremely light and small and they cannot be seen. Indirect methods have been utilized to determine the absolute mass of an atom...

Atomic orbital Molecular orbital An electron in atomic orbital isunder 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 atoms..

Dalton's Atomic Theory - 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..

Shapes of Atomic Orbitals - 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 an..

The atomic and ionic radii of alkaline Earth metals are smaller than the corresponding members of the alkali metals. This is due to the fact of Group 2 elements having a higher nuclear charge allow electrons to be attracted more towards the nucleus. This reduces the size of atomic..