– In this subject, we will discuss the difference Between Electronegativity and Electron Affinity Electron Affinity  – A neutral atom can accept an electron to form a negative ion. In this process, in general, energy is released. – The electron affinity (EA) of an element is the amount of energy released …

– The ionization energy (IE) of an element is defined as the energy needed to remove a single electron from an atom of the element in the gaseous state. Ionization Energy – The process of removing an electron from an isolated atom to form a positive ion is called ionization. …

– In this subject, we will discuss the rules of Electron Configuration Of Elements  Electron Configuration Of Elements – We have seen before that to define completely the state of an atom it is obligatory to refer to all the four quantum numbers (n, l, m, and s) of every …

– In this subject, we will discuss the Distribution of Electrons in Orbitals according to Hund’s Rule. Energy Distribution and Orbitals – In our earlier discussion, we have seen that the energy of an electron is determined by the first two quantum numbers (n) and (l), while the other two …

– The Pauli exclusion principle is of immense value in telling the maximum number of electrons accommodated in any shell. Quantum Numbers and the Energy of an Orbital – The nature of an electron, its position, and energy, is fully implied only by mentioning the values of four quantum numbers ascribed …

Quantum Numbers – Bohr’s electronic energy shells or levels, designated as Principal Quantum Numbers (n), could hardly explain the hydrogen spectrum adequately. – Spectra of other elements that are quite complex, also remained unexplained by this concept. – Many single lines of the spectra are found to consist of a …

Schrödinger Wave Equation – In order to provide sense and meaning to the probability approach, Schrödinger derived an equation known after his name as the Schrödinger Wave Equation.  – Calculation of the probability of finding the electron at various points in an atom was the main problem before Schrödinger.  – …

– Heisenberg’s uncertainty Principle: As it is impossible to know the position and the velocity of any one electron on account of its small size, the best we can do is to speak of the probability or relative chance of finding an electron with a probable velocity. Heisenberg’s Uncertainty Principle …

1. In the spectrum of hydrogen atom, the series which falls in ultraviolet region is_______ (a) Lyman series (b) Balmer series (c) Paschen series (d) Brackett series Answer. (a) 2. The e/m value for the particles constituting cathode rays is the same regardless of_______ (a) the gas present in cathode …

De Broglie Equation – de Broglie had arrived at his hypothesis (de Broglie equation) with the help of Planck’s Quantum Theory and Einstein’s Theory of Relativity. – He derived a relationship between the magnitude of the wavelength associated with the mass (m) of a moving body and its velocity. – …

Zeeman Effect – In 1896 Zeeman discovered that spectral lines are split up into components when the source emitting lines is placed in a strong magnetic field. It is called the Zeeman effect after the name of the discoverer. – The apparatus used to observe the Zeeman effect is shown …

– The Bohr-Bury scheme considers that the maximum number of electrons that each orbit can contain is 2 × n2, where n is the number of orbits. – Having known that planetary electrons numerically equal to the atomic number are revolving about the atomic nucleus in closed orbits, the question …

– Bohr theory was based on Planck’s quantum theory and was built on some postulates. – Rutherford’s nuclear model simply stated that atom had a nucleus and the negative electrons were present outside the nucleus. – It did not say anything as to how and where those electrons were arranged. …

– In this subject, we will discuss the Photoelectric Effect and Compton Effect Photoelectric Effect – When a beam of light of sufficiently high frequency is allowed to strike a metal surface in a vacuum, electrons are ejected from the metal surface. – This phenomenon is known as the Photoelectric …

– In this subject, we will discuss the atomic Spectrum of Hydrogen Atomic Spectrum – When an element in the vapour or the gaseous state is heated in a flame or a discharge tube, the atoms are excited (energised) and emit light radiations of a characteristic colour. – The colour …

– In this subject, we will discuss the Atomic Number and Mass Number Mosley’s Determination of Atomic Number – The discovery that an atom has a nucleus that carries a positive charge raised the question: What is the magnitude of the positive charge? – This question was answered by Henry …

– In this subject, we will discuss the Rutherford’s Atomic Model (Experiment, Postulates, weakness) Alpha particles – Alpha particles are shot out from radioactive elements with very high speed. – For example, they come from radium atoms at a speed of 1.5 × 107m/sec. – Rutherford identified them to be …

– In this subject, we will discuss the Subatomic Particles: Electrons, Protons, and Neutrons Subatomic Particles – We have hitherto studied the properties of the three principal fundamental particles of the atom, namely the electron, proton, and neutron. – These are summarised in this Table:   – Nearly all of …

Cathode Rays – The discovery of electron – The knowledge about the electron was derived as a result of the study of the electric discharge in the discharge tube (J.J. Thomson, 1896). (1) The discharge tube consists of a glass tube with metal electrodes fused in the walls. (2) Through …

– In this subject, we will discuss the Substituted Cyclohexane: Axial and Equatorial Hydrogen Groups Substituted Cyclohexane: Axial and Equatorial Hydrogen Groups – The six-membered ring is the most common ring found among nature’s organic molecules. – For this reason, we shall give it special attention. – We have already …