Valence Electrons

Electrons present in the outer most shell are called as Valence Electrons. They determine the chemical properties of the element. Valence electrons of charged atoms We know that electrons are negatively charged. When an atom […]


Recurrence of properties of elements after regular intervals based on the atomic numbers is called as periodicity. The modern periodic table is based on groups and periods and each element in a particular period exhibits similar […]

Modern Periodic Law

The modern periodic law states that physical and chemical properties of elements are periodic function of their atomic numbers. In 1913, Moseley proved that the most fundamental property of an element is its atomic number. So, […]

Electron Gain Enthalpy

Electron Gain Enthalpy(EGE) is the energy released when electron is added to an isolated gaseous atom. Factors affecting Electron Gain Enthalpy: Atom Size – In smaller atoms, incoming electrons are placed closed to the nucleus. […]

Ionization Enthalpy

Ionization Enthalpy is the energy required to remove one electron from isolated gaseous atom in ground state. It is also called as Ionisation energy or Ionisation Potential. Ionization Enthalpy Trends in Periodic Table Ist Ionization energy increases […]

Ionic Radius

Effective distance from the centre of the nucleus of the ion up-to which it has an influence in the bond. Ionic Radius Trends in Periodic Table When you move down the group in periodic table ionic radius […]

Vander Waals Radius

One half of the distance between nuclei of two neighboring molecules of the same element. When you bring two molecules of an element close to each other, then the distance between nucleus of these two molecules […]

Metallic Radius

A metallic radius is the measurement of an atom’s size with regards to metal elements only. One half of the distance between nuclei of two neighbouring atoms of a metal is called as metallic radii. Points […]

Covalent Radius

One half of the distance between nuclei of two covalently bonded atoms of same element in a molecule is called as covalent radius. Covalent radius is atomic radius of an element whose electrons are in […]

Atomic Radius

Atomic Radius is the distance from centre of the nucleus to the outermost shell of electrons. Trends in Periodic Table Atomic radius decreases across a period because electrons are added to the outermost shell which are […]