Category: 1st Year

Quantum numbers and their calculation

Definition: Quantum numbers are a set of four values that are used to describe the position and energy of the electron in an atom. Alternatively, quantum numbers are the numbers used to indicate the size, shape, three-dimensional direction, variation of the energy level, and the direction of rotation of an electron around its own axis. Four quantum numbers are required to fully describe the position of electrons in an atom…

(n+l) rule and its applications

(n+l) Rule From this rule, we can get information about the difference in energy between two orbitals. According to the Aufbau principle, electrons are filled into atomic orbitals in the increasing order of orbital energy level.(n+l) rule helps to determine which one between two given orbitals will occupy by an electron. As we know that there are four quantum numbers, namely, principal(n), azimuthal(l), magnetic(m), and spin(s) quantum numbers. They are…

Periodic properties: Electronegativity

When two different atoms in a molecule are bonded together by a covalent bond, the electron pair forming the the covalent bond is not shared equally by both the atoms. The relative ability of a bonded atom in a molecule to attract the shared electron pair towards itself is termed as its electronegativity. Factors affecting the magnitude of electronegativity: Size of the atom: The smaller atoms have greater electronegativity values…

Periodic Properties: Ionization Potential

Definition of ionization potential: The amount of energy needed to remove the most loosely bound electron from isolated neutral gaseous atom from its gaseous state to convert it into a unipositive gaseous cation. Unit: eV/atom ( 1 eV = 96.4705 KJ/mole = 23.06 Kcal/mole) Kcal/mole ( 1 Kcal/mole = 4.185 Kj/mole) KJ/mole Factors effecting the magnitude of Ionization Potential Effective nuclear charge: Greater is the magnitude of effective nuclear charge,…

Periodic Properties: Ionic radii (Part-02)

Size of anion: An anion is formed by adding one or more electrons to the neutral atom. F = 1s22s22p5 , F– = 1s22s22p6 O = 1s22s22p4 and O2- = 1s22s22p6 An anion has more electrons than its parent atom. With the increase of the number of electrons, the magnitude of the screening constant also increases. Therefore, the magnitude of the effective nuclear charge also decreases. The decreased effective nuclear…

Periodic Properties of Elements

The elements belonging the same group have similar properties. We have to pass 2, 8, 8, 18, 18, 32 and 32 elements before we come across an element with similar properties. The repetition of the elements with similar properties in the order of increasing atomic number as in the periodic table is called periodicity of properties and 2,8, 18 and 32 are called magic numbers. Causes of periodicity of properties:…

Factors affecting the magnitude of lattice enthalpy

The term lattice enthalpy can be defined by the following ways: The amount of energy released, when one mole of an ionic crystal is made from the requisite number of gaseous cations and anions, is named lattice energy The amount of energy, which is required to break down/ separate one mole of an ionic compound into its constituent isolated gaseous ions The amount of energy, which is liberated when 1…

Factors affecting the magnitude of solvation or hydration energy

Definition of solvation energy: When a gaseous cation or a gaseous anion interacts with the solvents forming a solvated cation or a solvated anion and in this process energy is liberated, which is called solvation energy. If water is used as a solvent, then gaseous cation or gaseous anion forms hydrated ion, and the liberated energy associated with this process is termed as a hydration energy. M + (g) +…

How to write your first e-mail to mange research supervisor

Sub: How to write email (first) to manage your supervisor! Samaple 1 Dear Respected Professor This is …….(Your name). I am writing from ……(your country). Recently, I have read your some published papers, which have attracted me a lot to write an email to you.  I obtained my M.Sc. degree in Chemistry from ………( name of your university). During my M.Sc study, I prepared some ……( summary of your thesis…

How to get scholarship in China for your higher study

Level: Ph.DField: Coordination Chemistry In order to get admission in a reputed university situated in China, One should have the information about available scholarships. Like S. Korea and Japan, there are two types of scholarships in China: Scholarships from Supervisor’s project  Scholarships offered by the Chinese Government  For both scholarships,  the first task of a candidate is to manage a supervisor. In order to manage a supervisor, candidate needs to…

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