Example: Se Se

1s22s22p63s23p64s23d104p4 = [Ar] 4s23d104p4 Example: Se Se

Clicker #1 How many unpaired electrons and valence electrons does Se have? A) 0; 14 B) 2; 6 C) 2; 14 D) 0; 6 E) 2; 4

Atomic Trends H F Fr Atomic Radius: size of the orbital decreasing increasing Fr

Atomic Trends H F Fr Atomic Radius: size of the orbital decreasing More protons = more attraction and smaller radius Orbitals are getting bigger and further from nucleus increasing Fr

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

Atomic Trends Ionization Energy increasing H F decreasing Fr

Atomic Trends H F Fr Ionization Energy increasing decreasing Electron is at its lowest energy state when closest to the nucleus takes more energy to take an electron away when closer to the nucleus decreasing Fr

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

Isoelectronic Series Same number of electrons Example: Which is larger Na+ or Ne?

Isoelectronic Series Same number of electrons Example: Which is larger Na+ or Ne? Same number of electrons but Na+ has 11 protons and Ne has 10 protons.

Example Which is larger Cl- or Ar? Which has a higher ionization energy Cl- or Ar?

Example Which is larger Cl- or Ar? Which has a higher ionization energy Cl- or Ar?

BONDING “Forces” What is meant by a “chemical bond”? Why do atoms bond to form molecules? How do atoms bond to form molecules?

BONDING Two Types of Bonding Intramolecular (within a molecule) Intermolecular (between molecules)

Ionic Compounds Between a metal and a nonmetal Example: NaCl Na: [Ne]3s1 Cl: [Ne]3s23p5

Ionic Compounds Between a metal and a nonmetal Example: NaCl Na: [Ne]3s1 Na+: [Ne] Cl: [Ne]3s23p5 Cl-: [Ne] 3s23p6

Mg -> Mg+ -> Mg2+ OVERALL = EXOTHERMIC PROCESS Ionization energies of atoms are highly endothermic HOWEVER… Takes more energy to remove 2nd electron Once you get Mg2+ (noble gas configuration) gives off energy OVERALL = EXOTHERMIC PROCESS

Bonding in H2 Is this ionic?

Bonding in H2 Covalent Bonding Sharing electrons Hydrogens share the electrons and have noble gas configuration Why isn’t He diatomic?

Bonding in H2 Covalent Bonding Sharing electrons Hydrogens share the electrons and have noble gas configuration Why isn’t He diatomic? Already has a noble gas configuration

Therefore… Covalent bonding has same idea as ionic bonding… But Neither atom is “strong” enough to remove electron from the other atom

What about CO?