M4 Exam

Question 1 1. Write electron (subshell) configurations for the following atoms: 19 K 35 Br Answer: ELECTRON CONFIGURATIONS 19 K = 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 35 Br = 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 Question 2 2. Write orbital diagrams for the following atoms: 15 P 28 Ni Answer: ORBITAL DIAGRAMS 15 P = 1s 2 2s 2 2p 6 3s 2 3p 3 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ ↑ 1s 2s 2p 3s 3p 28 Ni = 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 8 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ 1s 2s 2p 3s 3p 4s 3d Question 3 Write the values for the four quantum numbers for a 4d 8 electron. Answer:

A 4d 8 electron is in the 4th shell so n = 4. Its "d" orbital has 2 nodal planes so l = 2. The electron is in the 3rd of the orbitals of the d subshell so m l = 0. And since this is the 2nd electron to occupy this "d" orbital, m s = -1/2. In summary, the values for the four quantum numbers for the 4d 8 electron are: n = 4, l = 2, m l = 0 and m s = -1/2. Question 4 Write the values for the four quantum numbers for the last electron to fill 28 Ni. Answer: The last electron to fill 28 Ni is a 3d 8 electron which is in the 3rd shell so n = 3. Its "d" orbital has 2 nodal planes so l = 2. The electron is in the 3rd of the orbitals of the d subshell so m l = 0. And since this is the 2nd electron to occupy this "d" orbital, m s = - 1/2. In summary, the values for the four quantum numbers for the 3d 8 electron are: n = 3, l = 2, m l = 0 and m s = -1/2. Question 5 Choose the atom that matches the identified atomic property and explain answer based on the periodic trend and its position within a group or period in the periodic table. Highest Ionization Energy: Li, Be, B Answer: B has the highest ionization energy since it is farthest to right of these elements and ionization energy increases as you go from left to right in a period. 0 Question 6 Choose the atom that matches the identified atomic property and explain answer based on the periodic trend and its position within a group or period in the periodic table . Lowest Electronegativity: Li, Be, B Answer: Li has the lowest electronegativity since it is farthest to left of these elements and electronegativity increases as you go from left to right in a period.

Write the subshell electron configuration (i.e.1s2 2s2, etc.) for the P15 atom and identify which are valence (outer shell) electrons and determine how many valence electrons there are. Answer: P15 = 15 electrons = 1s2 2s2 2p6 3s2 3p3 = 5 valence electrons Question 12 Using up and down arrows, write the orbital diagram for the Ti22 atom. Answer: Ti22 = 1s2 2s2 2p6 3s2 3p6 4s2 3d2 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ Question 13 Using up and down arrows, write the orbital diagram for the V23 atom and identify which are unpaired electrons and determine how many unpaired electrons there are. Answer: V23 = 1s2 2s2 2p6 3s2 3p6 4s2 3d3 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ ↑ = 3 unpaired electrons Question 14 Write the subshell electron configuration (i.e.1s2 2s2, etc.) for the Fe26 atom and then identify the last electron to fill and write the 4 quantum numbers (n, l, ml and ms) for this electron. Answer: Fe26 = 1s2 2s2 2p6 3s2 3p6 4s2 3d6 : n=3, l=2, ml = -2, ms = -1/2 Question 15 1. Arrange the following elements in a vertical list from smallest (top) to largest (bottom) atomic size: Cl, F, Br 2. Arrange the following elements in a vertical list from highest (top) to lowest (bottom) electronegativity: S, Si, P 3. Arrange the following elements in a vertical list from lowest (top) to highest (bottom) ionization energy: S, Te, Se Answer: 1. F

Cl Br 2. S P Si 3. Te Se S Question 16 1. List and explain which of the following atoms forms a positive ion with more difficulty. Sn or I 2. List and explain which of the following is the smaller atom. Sn or Te Answer: 1. I forms a positive ion less easily than Sn since ionization potential increases as you go to the right in a period which means that I with the higher ionization potential requires more energy to lose an electron and form a positive ion so it does so less easily. 2. Te is smaller than Sn since atomic size decreases as you go to the right in a period which means that Te which is further to the right is smaller. Question 17 On a piece of scratch paper, draw the orbital configuration of the C6 atom and use it to draw the Lewis structure for the C6 atom. Then choose the correct Lewis structure for C6 from the options listed below. Answer: . :C. Question 18 On a piece of scratch paper, draw the orbital configuration of the As33 atom and use it to draw the Lewis structure for the As33 atom. Then choose the