Unformatted text preview: Workshop #3 Chem 1A Fall 2010 1. The element is used in the semiconductor industry. A) Provide the quantum number (n, l, ml, ms) for each electron in the n=3 shell. B) give the shape of these orbitals. n = 3, l = 0, 1, 2; for l = 0, ml = 0; for l = 1, ml = -1, 0, 1; for l = 2, ml = -2, -1, 0, 1, 2. Silicon has 4 valence electrons. (3, 0, 0, ), (3, 0, 0,- ), (3, 1, -1, ), (3, 1, 0, ) According to Hund’s Rule the two electrons in the p orbitals should have parallel spins. These spins can be in any combination of the ml = -1, 0, 1 orbital. These electrons must also have the same sign, either + or - . 2. Using the de Broglie equation ( , m = mass, u = velocity) calculate the wavelength and frequency of a) a fastball (baseball = 149 g) thrown @ 43.809 m/s; b) an electron of mass 9.11•10-31 kg moving at 1.89•107 m/s. Calculate the kinetic energy of each particle (KE = ). For a baseball:
( )( ) ( )( ) For electron:
( )( ) ( )( ) 3. Write the full ground state electron configuration for each of the elements represented by each of following atomic numbers. Z 19 Electron Configuration 1s22s22p63s23p64s1 or [Ar]4s1 potassium 1s22s22p63s23p64s13d5 or [Ar]4s13d5 chromium 1s22s22p63s23p64s23d5 or [Ar]4s23d5 manganese 24 25 What are the elements above? 4. Nitrogen, N2, requires an enormous amount of energy to break the triple bond joining the two nitrogen atoms, 945.3 kJ/mol. How much energy does it take to break the triple bond in a single molecule of N2? Calculate the wavelength and frequency of a photon powerful enough to break the N2 triple bond. ( )( )( ) 5. Hund = Electron configurations are most stable when unpaired electrons have parallel spins Schrödinger = Developed the equation to describe the quantum properties of an atom. Pauli = Pauli Exclusion Principle, no 2 electrons can have same four quantum numbers Aufbau principle = As protons are added to the nucleus, electrons are added to the lowest energy atomic orbitals Heisenberg = Heisenberg Uncertainty Principle, ...
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