Forces of attraction and repulsion between interacting atoms/molecules other than electrostatic or covalent bonds are called inter molecular forces. Attractive inter molecular forces: Known as van der Waal’s forces Types: 1. Dispersion forces/ London forces: Force of attraction between temporary dipoles. Always attractive. Significant only at short distances between interacting particles Magnitude depends on polarizability Read more about Intermolecular forces[…]
Polarity: All homonuclear diatomic molecules will have zero polarity. Example: O2, N2, F2, H2. It mainly arises due to differences in electronegativity of bonded atoms. A covalent bond, in which electrons are shared unequally and the bonded atoms acquire partial positive and negative charge, is called a polar covalent bond (or) a covalent bond (or) Read more about Bond Parameters II[…]
1. Bond Length: It is the equilibrium distance between the nuclei of two bonded atoms in a molecule. The covalent radius is the radius of an atom’s core which is in contact with the core of an adjacent atom in a bonded situation. If two similar atoms are joined by a covalent bond in the Read more about Bond Parameters[…]
Electronic configuration and Molecular Behavior: The distribution of electrons among various molecular orbitals is called the electronic configuration of the molecule. Important information of configuration: a) Stability of Molecules: The molecule is stable if NB is greater than NA The molecule is unstable if NB is less than NA. Where NB → Bonding e⁻s NA Read more about Applications of Molecular Orbit Theory[…]
Developed by F. Hund and R.S. Mulliken in 1932 Features of this theory: The electrons in a molecule are present in the various Molecular orbitals. The atomic orbitals of comparable energies and proper symmetry combine to form molecular orbitals. In a molecular orbital an electron is influenced by two or more nuclei depending upon the Read more about Molecular Orbital Theory[…]
Hybridisation of Elements involving d Orbitals The elements which contain d orbitals in addition to s and p orbitals form hybrid orbitals with s, p and d orbitals. The hybridisation involves either [3s, 3p and 3d] or [3d, 4s and 4p] (as the energies of these orbitals are comparable). However, since the difference in energies Read more about Hybridisation – II[…]
Introduced by Pauling The atomic orbitals combine to form new set of equivalent orbitals known as hybrid orbitals. Unlike pure orbitals, the hybrid orbitals are used in bond formation. Hybridization: The process of intermixing of the orbitals of slightly different energies so as to redistribute their energies, resulting in the formation of new set of Read more about Hybridisation[…]
Ionisation Energy: It is the amount of energy required to remove an electron from the outermost orbit of an isolated gaseous atom. (If given in terms of the amount of work done in removing an electron, the property is called ionization potential.) Units: kJ / mol (for ionization potential, units: eV/atom.) This is denoted by word I. Read more about Trends in Chemical Properties of Periodic Elements[…]
1. Periodicity in valency or oxidation states: Thevalence (or valency) of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules. The valence of elements is usually (though not necessarily) equal to the number of electrons in the outermost orbitals and/ or equal to eight minus the number Read more about Periodic Trends in Properties of Elements[…]
1. Atomic Radius: It is defined as the distance from the centre of the nucleus to the outermost shell of electrons. For practical purposes, atomic radius can be defined in many ways. a) Covalent Radius: Half of the inter-nuclear distance between two identical or almost identical atoms bonded by a single covalent bond. For a diatomic molecule, Read more about Trends in Physical Properties of Periodic Elements[…]