How are electron arrangements in orbits?

Electron arrangements in orbits: Having known that planetary electrons numerically equal to the atomic number are revolving about the atomic nucleus in closed orbits, the question arises as to how they are arranged in these orbits. Langmuir Scheme Langmuir deserves credit for proposing the first detailed system for the organization of extranuclear electrons in 1919. … Read more

Sommerfeld’s modification of bohr atom

Sommerfeld atomic model: When spectrometers were used to study spectra, each line was discovered to be made up of many closely packed lines. On the basis of Bohr’s hypothesis, the occurrence of these numerous spectral lines could not be explained. Sommerfeld made the following changes to Bohr’s theory. Although Bohr regarded electron orbits to be … Read more

Bohr’s Theory (Bohr model of the atom)

The nuclear model of Rutherford essentially claimed that an atom had a nucleus and that the negative electrons were present outside the nucleus. It made no mention of how or where the electrons were organized. It also couldn’t explain why, despite electrostatic pull, electrons didn’t fall into the nucleus. Niels Bohr presented a new model … Read more

Compton effect

A.H. Compton presented another evidence of the quantum theory, or photon theory, in 1923. In 1927, he was awarded the Nobel Prize for his discovery of the Compton Effect. When X-rays of wavelength’ contacted a piece of graphite, one electron was expelled, and the X-rays scattered at an angle had a longer wavelength, he proved. … Read more

Photoelectric effect

Photoelectric effect When a sufficiently high-frequency beam of light is permitted to impact a metal surface in a vacuum, electrons are expelled from the metal surface. The expelled electrons are known as Photoelectrons, and the process is known as the Photoelectric effect. The photoelectric effect, for example, happens when ultraviolet light shines on Cs (or … Read more

Quantum theory of radiation

Quantum theory of radiation: The wave hypothesis of radiant energy transmission seemed to indicate that energy was released (or absorbed) in waves. Max Planck investigated the spectral lines produced from hot-body radiations at various temperatures in 1900. According to him, light radiation was created intermittently by the heated body’s molecules, each of which vibrated at … Read more

The atomic spectrum of hydrogen

Atomic spectrum of hydrogen The emission line spectrum of hydrogen can be obtained by passing an electric discharge through the gas contained in a discharge tube at low pressure. The light radiation emitted is then examined with the help of a spectroscope. The bright lines recorded on the photographic plate constitute the atomic spectrum of … Read more

Pharmaceutical microbiology Question bank B pharmacy

Pharmaceutical Microbiology Important questions all unit 3rd sem B pharmacy This Pharmaceutical microbiology Question bank was released by Rajiv Gandhi University of health and science Bangalore, this questions bank is arranged according to the syllabus, and unit-wise. It contains all the possible important questions of important topics. PHARMACEUTICAL MICROBIOLOGY QUESTION BANK UNIT 1 pharmacetical microbiology … Read more

What is the electromagnetic spectrum in chemistry

The electromagnetic spectrum The Electromagnetic radiation spectrum, or simply the Electromagnetic spectrum, is made up of a variety of wavelengths emitted by electromagnetic radiation. The electromagnetic spectrum with wavelengths denoted is seen in the diagram below. Continuous spectrum in chemistry White light is radiant energy coming from the sun or from incandescent lamps. It is … Read more