userdata-paziras-Chem101-Chap_07A

Highenergyco llisio n between mo leculeswill

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Unformatted text preview: s in atom, called energy levels Consequence: · The atom can have only specific energy values. · Bohr derived a formula which can be used to calculate the energy values for the electron in the H atom RH E = - -¾¾ 2 n where: RH = constant = 2.179 x 10-18 J n = an integer, which can have the fo llow values: 1, 2, 3, 4, 5….¥ (also called the pr incipal quantum number) 2. TRANSITIONS BETWEEN ENERGY LEVELS An electron in an atom can change energy only by going fro m one energy level to another level. The electron undergoes a transit ion. a) Emission of Light Energy · An electron in a higher energy level (initial energy level, Ei ) undergoes a transit ion to a lower energy level (final energy level, Ef) Ei e In this process, the electron loses energy, which is emitted by the atom as a photon Result: A bright line appears in the line spectrum Ef Energy of the emitted photon = Ei - Ef = hn 11 Chemistry 101 Chapter 7 b) Absorbtion of Heat or Electrical Energy · Normally, the electron in the H atom exists in its lowest energy level (n = 1) · To get into a higher energy level, the electron must gain energy or get excited. When Hydrogen gas is heated, its mo lecules move much faster. High energy co llisio n between...
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This document was uploaded on 03/18/2014 for the course CHEM 101 at Los Angeles Mission College.

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