Creating a Positive Learning Environment for Everyone Be respectful of your classmates Save conversation for clicker portions of lecture Put cell phones in “airplane” mode Turn off tablets Close laptops

Joke of the Day Q: Why did the turkey cross the road before Thanksgiving? A: He was trying to give people the impression that he was a chicken. (Even though it wasn’t a chemistry joke, I slapped my neon that one it was so funny.)

Announcements Lon-capa HW 6 – Type 1 due Monday (11/27) and Type 2 due Wednesday (11/29) by 7pm “Lab 5: Modern Atomic Theory” write-up due tomorrow in discussion (and text homework) Exam 3 is Thursday December 7

Valence Electrons Highest or outermost energy level electrons Where the chemistry happens!  Look at principal quantum level n Look at group or family Sulfur: 1s22s22p63s23p4 Valence electrons are in n = 3 level Valence electrons = 2 + 4 = 6 electrons

Number of Valence Electrons in…? P Br 1s22s22p4 [Ar]5s24d105p3 2 5 7 6 5

Clicker #1 How many unpaired electrons are in a neutral ground state atom of phosphorus? A) 1 B) 3 C) 5 D) 7 E) 15

Atomic Radius (Size) Increases down a group Hydrogen Francium Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels

Atomic Radius (Size) Decreases across a row (period) – outer electrons in the same energy level Lithium Fluorine DECREASES! More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly, pulling them in and shrinking the size.

Clicker #2 Which of the following elements has the largest atomic radius? A) Ca B) Al C) N D) Sr E) F

General Trend (Atomic Size/Radius)

Ionization Energy Decreases down a group Hydrogen Francium Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels. Electrons are not as tightly bound by the nucleus at higher energy levels so it takes less energy to remove an outer electron.

Ionization Energy Increases across a row (period) – outer electrons in the same energy level Lithium Fluorine INCREASES! More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly and pulling them in closer to the nucleus, requiring MORE energy to remove an outer electron.

Clicker #3 Which of the following elements has the largest ionization energy? A) P B) Al C) Cl D) Ba E) K

General Trend (Ionization Energy)

Clicker #4 What are the electron configurations of Na+ and F-? Na+ F- 1s22s22p63s1 1s22s22p5 b) 1s22s22p63s2 1s22s22p4 c) 1s22s22p6

Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure Molecular Properties

Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure Molecular Properties

Bond (Intramolecular) Force that holds groups of two or more atoms together and makes them function as a unit. Bond is more stable than the two separated atoms (lower energy state).

Ionic Bonding

Ionic Bonding

Covalent Bonding

Electronegativity

Covalent Bonding

Polar Covalent Bonding

Polar Covalent Bonding

Clicker #5 Rank the following bonds from least polar to most polar: Si-Cl P-Cl Mg-Cl S-Cl A) S-Cl, P-Cl, Mg-Cl, Si-Cl B) P-Cl, S-Cl, Si-Cl, Mg-Cl C) Mg-Cl, Si-Cl, P-Cl, S-Cl D) Mg-Cl, S-Cl, P-Cl, Si-Cl E) S-Cl, P-Cl, Si-Cl, Mg-Cl