Use your textbook or other resources available to answer the following questions

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1 Use your textbook or other resources available to answer the following questions General Information: Quantum Numbers Wave Function - Is characterized by four parameters, know as quantum numbers, which describes the probability of finding an electron in 3-D space. Principal Quantum Number: Symbol: n n = 1, 2, 3, 4, etc. Angular Momentum Quantum Number: Symbol: l Describes 3-D space/shape of orbital Range = 0 to n-1 The angular momentum quantum number (l) is also represented with a letter, which tells us about the shape of the orbital l = 0 s l = 1 p l = 2 d l = 3 f l = 4 g l = 5 h Magnetic Quantum Number: Symbol: m l Defines spatial orientation/rotation around an axis Range = -l to l Total Number: 2l + 1 Spin Quantum Number: Symbol: m s Electrons spin - +1/2 or -1/2 Pauli Exclusion Priniciple No two electrons in an atom can have the same four quantum numbers Otherwise there could be two electrons in the exact same place! Electron Configuration A description of the orbitals that are occupied by electrons in an atom. Ground State Electron Configuration The lowest energy electron configuration. 1

2 We use Aufbau Principle to fill the orbitals: 115 PLTL Activity Sheet # 11 Lower energy orbitals fill before higher energy orbitals 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, etc. An orbital can only hold 2 electrons which must have opposite spins If 2 or more degenerative orbitals are available, 1 electron goes into each until all are half full Hund s Rule If 2 or more orbitals with degenerate energy levels are available, 1 electron goes in each with the same spin until all are half filled Activity 1: Complete the following problems. 1. Fill in the blanks in the chart that follows. Be sure to include all possible quantum numbers. The second row is completed as an example. n Possible subshell Possible values of m l # orbitals in subshell values of l s p 1, 0, Consider a ground state atom of Magnesium, which has two valence electrons. The quantum numbers for one of the valence electrons is n=3, l=0, ml=0, and ms= ½. What are the quantum numbers for the other electron? 3. The ground state electron configuration for the single electron in the Li 2+ ion is 1s 1. What are the values of the m l and m s quantum numbers for this electron? Explain 2

3 4. Consider an atom of helium in the ground state with two electrons. The quantum numbers for one of the valence electrons is n=1, l=0, ml=0, and ms=+½. What are the quantum numbers for the other electron? Write the electron configuration for the ground state of helium. Activity 2: Which of the following rules is being violated in each electron configuration below? Explain your answer for each. Hund s Rule, Pauli Exclusion Principle, Aufbau Principle 1s 2s 2p _ _ 1s 2s 2p 3s 3p _ 1s 2s 2p 3s 3p 1s 2s 2p 3s 3p 3d Activity 3: Complete the following problems. Begin by assigning one of each of the following elements to each group member: carbon, nitrogen, oxygen, fluorine, neon, sodium, aluminum, magnesium. Add more elements as necessary so that each has their own unique element. Each person should complete the following five steps for his or her own element. Step 1 Step 2 Step 3 Step 4 Step 5 Write the electron configuration for your element Prepare a table similar to the one below, giving the four quantum numbers for each electron in a ground state atom of your element Fill in your table Create an energy level diagram for your element. Use a line to represent an orbital, and use up and down arrows to represent electrons in each orbital Fill in the energy level diagram 3

4 Here are the steps completed for the element boron Step 1 B: 1s 2 2s 2 2p 1 Step 2 & Step 3 Step 4 & Step 5 2p 2s 1s n l ml ms ½ ½ ½ ½ ½. 4

5 Activity 4: Complete the following in a round robin fashion. a. How many 4p electrons does the ground state bromine atom have? b. Give the complete set of quantum numbers for all of the bromine 4p electrons c. How many d electrons does the ground state cobalt atom have d. Considering the ground state, how many unpaired electrons are in a bromine atom? A cobalt atom? And a phosphorous atom? General Information: Para- and Diamagnetism Paramagnetism Substances with unpaired electrons Attracted to a magnetic field Diamagnetism Substances with no unpaired electrons No attraction to a magnetic field In order to determine magnetism, you will have to write the electron configuration and create an energy level diagram. 1. Which of the following elements or ions do you expect to be paramagnetic? Which are diamagnetic? Explain K Ba 2+ Fe 2+ Fe 3+ F F Ni 2+ 5

6 2. How do the species above react differently in the presence of a magnetic field? Be specific Which are repelled? Which are attracted? Activity 5: Write the unabbreviated electron configurations of the following elements. Sodium: Iron: Bromine: Barium: Neptunium: Activity 6: Write the abbreviated electron configurations of the following elements. Cobalt: Silver: Tellurium: Radium: Lawrencium: Activity 7: Determine what elements are denoted by the following electron configurations. 1s 2 2s 2 2p 6 3s 2 3p 4 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1 [Kr] 5s 2 4d 10 5p 3 [Xe] 6s 2 4f 14 5d 6 [Rn] 7s 2 5f 11 Activity 8: Determine which of the following electron configurations are not valid. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 4d 10 4p 5 1s 2 2s 2 2p 6 3s 3 3d 5 [Ra] 7s 2 5f 8 [Kr] 5s 2 4d 10 5p 5 [Xe] 6