Bohr Model

2617 WordsDec 22, 201411 Pages
Postulates of Dalton’s Atomic Theory The main points of Dalton’s atomic theory, an explanation of the structure of matter in terms of different combinations of very small particles, are given by the following postulates: 1. All matter is composed of indivisible atoms. An atom is an extremely small particle of matter that retains its identity during chemical reactions. 2. An element is a type of matter composed of only one kind of atom, each atom of a given kind having the same properties. Mass is one such property. Thus, the atoms of a given element have a characteristic mass. 3. A compound is a type of matter composed of atoms of two or more elements chemically combined in fixed proportions. The relative numbers of any two kinds of…show more content…
5. It does not predict the relative intensities of spectral lines. 6. The Bohr Model does not explain fine structure and hyperfine structure in spectral lines. 7. It does not explain the Zeeman Effect. Main Points of the Bohr-Sommerfeld Model: Electrons are revolving around the nucleus not only in circular paths but also in some electrical paths. These energy gaps are so close that normal machine cannot visualize them. We can explain the multiplicity of hydrogen Atom via this model. According to quantum mechanics, each electron in an atom is described by four different quantum numbers, three of which (n, l, and ml) specify the wave function that gives the probability of finding the electron at various points in space. < A wave function for an electron in an atom is called an atomic orbital. An atomic orbital is pictured qualitatively by describing the region of space where there is high probability of finding the electrons. The atomic orbital so pictured has a definite shape. A fourth quantum number (ms) refers to a magnetic property of electrons called spin. We first look at quantum numbers, then at atomic orbitals. Quantum numbers: Numbers to state the exact position of an electron inside an atom are called Quantum numbers. 1. Principal Quantum Number (n): this quantum number is the one on which The energy of an electron in an atom principally depends; it can have any positive value: 1, 2, 3, and so on. 2. Angular
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