Chemistry – Nov 14, 2016 P3 Challenge- Objective – Which is smaller? N or P Which is larger? K+ or K Which has the higher ionization energy? K or Br Which has the higher electronegativity? O or Br Objective – Quantum Mechanics / Atomic Structure (Get out your colored periodic table) Get out Periodic Trends Worksheet for Hmk Check

Chemistry – Nov 14, 2016 Objective – Agenda Atomic Structure / Quantum Mechanics Agenda Homework Review Bohr model review, QM overview Orbital Shapes Organization of orbitals Filling order 2D images (given time) Assignment: Quantum Numbers Worksheet

Homework Review 1. O, C, Al, K 2. Ne, Al, S, O (noble gases = 0) 3. F is smaller atom, higher on PT, harder to remove electron from F than I 4. same group 5. a. decrease b. increase c. increase 6. Atomic Radii increase going down PT, Re: more electrons repel each other 7. Ionization E increase going L R, Re: same size, but Z is increasing.

Homework Review 8. a. Al Al is lower on PT b. Na same period, Al is smaller due to higher Z c. S S is lower on PT d. O same period, O is larger because it’s to the left e. Br Br lower on PT f. Ca Ca lower on PT 9. a. Be I.E increases L R b. Ca Ca is smaller c. Na Na is smaller d. Ar Ar noble gas, I.E increases L R e. Cl I.E increases L R f. Li Li is smaller

Homework Review 10. a. Ga Ga to the right b. Br Br to the right c. O O to the right d. Sr Sr is above Ba e. Cl Cl is to the right f. O O is above S 11. a. Ca Cations get smaller b. Br– anions get larger c. Na+ Isoelectronic, Na has lower Z d. Ba+2 Ba is below Sr e. Cl– isoelectronic, Cl has lower Z f. S–2 S is below O

Bohr model and Quantum models Recall the Bohr model that uses quantized orbits Recall Quantum Mechanics that uses quantized orbitals Orbitals that we draw represent a 90% probability of finding an electron in that space. Any single orbital can contain up to two electrons (0, 1, or 2)

Quantum Mechanics Same as Bohr model except for how the energy levels are described. Electrons located in orbitals. Mathematical description is a “wave function” - Schrödinger Explains the wave property of matter. Strategy to understand QM: Learn what the orbitals look like and how they’re organized on H atom Populate the orbitals with electrons to describe other atoms

Shapes of Orbitals The bigger an orbital, the higher the energy level The more complicated the shape, the higher the energy level. Using different shapes is how QM creates its quantized energy levels. Four different basic orbital shapes: s p d f Basic shapes double the number of lobes for each level:

P, D, and F Orbitals

Quantum Mechanics Atomic Model - Electrons organized on 4 levels 1) Shells 1, 2, 3, 4, 5, 6, 7 2) Subshells s, p, d, f 3) Orbitals 4) An orbital can hold up to two electrons. S subshells contain 1 orbital (room for 2 e) P subshells contain 3 orbitals (6 e) D subshells contain 5 orbitals (10 e) F subshells contain 7 orbitals (14 e) Shell 1 – s (2e) Shell 2 – s and p (8e) Shell 3 – s and p and d (18e) Shell 4 – s and p and d and f (32e) Shell 5 – s and p and d and f (32e) Shell 6 – s and p and d (18e) Shell 7 – s and p (8e) 2 + 8 + 18 + 32 + 32 + 18 + 8 = 118 Structure for all 118 known elements.

Each small box with a 2 represents a single empty orbital that has a capacity of 2 electrons.

Subscripts (x, y, z, xy, yz etc… Quantum Numbers Four Quantum Numbers used to describe the structure. Memory items. Quantum Number Name Allowed Values Determines Specifies a Common labels n Principle 1, 2, 3, 4….. Size and Energy Shell 1,2,3,4… (Period #) Angular Momentum 0, 1, 2… (only up to n-1) Shape Subshell s, p, d, f ml Magnetic Orientation Orbital Subscripts (x, y, z, xy, yz etc… ms Spin +½ or -½ Electron Up ↑, Down ↓

How Electrons Fill the Orbitals – the rules The orbitals are present on every atom, but only some have electrons located in them depending on how many electrons the atom has. Three guiding principles to use: 1) Aufbau Principle: Electrons live in the lowest energy orbitals possible. (Higher energy orbitals remain empty.) 2) Hund’s Rule: Electrons would rather not live with another electron, but its better to be paired up than to live at a higher energy. If paired, they have opposite spins. 3) Pauli Exclusion principle: No two electrons can occupy the same space. No two electrons can have the same 4 quantum numbers

Orbital Energy Levels Energy levels are not intuitive because the energy levels of the shells overlap. Order of filling: 1s…2s, 2p…3s, 3p…. Then the shells start to overlap. …4s, 3d, 4p…5s, 4d, 5p… …6s, 4f, 5d, 6p…7s, 5f, 6d, 7p If that seems hard to remember, try this…

Shells 1-7 S block P block D block F block Periods 1 – 2 H = 1s 13-18 **actinides *lanthanides Shells 1-7 Periods S block 1 – 2 H = 1s P block 13-18 B = 2p D block 3-12 Sc = 3d F block Lanthanides Actinides La = 4f Lanthanum 57 La 138.91 Cerium 58 Ce 140.12 Praseodymium 59 Pr 140.91 Neodymium 60 Nd 144.24 Promethium 61 Pm (145) Samarium 62 Sm 150.36 Europium 63 Eu 151.97 Gadolinium 64 Gd 157.25 Terbium 65 Tb 158.93 Dysprosium 66 Dy 162.50 Holmium 67 Ho 164.93 Erbium 68 Er 167.26 Thulium 69 Tm 168.93 Ytterbium 70 Yb 173.04 Actinium 89 Ac (227) Thorium 90 Th 232.04 Protactinium 91 Pa 231.04 Uranium 92 U 238.03 Neptunium 93 Np (237) Plutonium 94 Pu (244) Americium 95 Am (243) Curium 96 Cm (247) Berkelium 97 Bk Californium 98 Cf (251) Einsteinium 99 Es (252) Fermium 100 Fm (257) Mendelevium 101 Md (258) Nobelium 102 No (259)

s p d f 1 1s 2 2s 2p 3 3s 3p 3d 4 4s 4p 4d 4f 5 5s 5p 5d 5f 6 6s 6p 6d 7 7s 7p

Exit Slip - Homework Exit Slip: Determine the highest energy subshell for Strontium and Silicon What’s Due? (Pending assignments to complete.) Quantum Numbers Worksheet What’s Next? (How to prepare for the next day) Read Holt p84 - 88