Teddy Roosevelt Becomes President After McKinley Assassination (1901) Reading: Chapter 5, sections 5, 6, 7 Mastering Chemistry Assignment #3 Chapter 4 #’s 16,17,20,36,38,46,50,52,54,56,72-88 evens, 98,102,110,117 Due TOMORROW 9/15/09 by 11:59 PM Average student took ~ 2 hours Nomenclature lists 1, 2, 3 Quiz Friday Tutoring

Electron Sub-Shells

Valence Electrons 2 v. e- 2 v. e- 5 v. e- 6 v. e- 1st shell  2nd shell  3rd shell  4th shell  5th shell  6th shell  7th shell 

Valence Electrons e- are found in discreet “energy levels” or “shells” Valence e- are the outermost e- in an atom The MOST important of the e- only “s” and “p” electrons count as valence e- 1st valence shell holds up to only 2 e-, all other valence shells hold up to 8 e-

15 protons How many electrons are needed to be neutral?

15 protons 2 electrons

15 protons 10 electrons

Stable!!! 15 protons 15 electrons Total charge = 0

Valence electrons are the outermost electrons

Stable!!! 15 protons 18 electrons Total charge = p+ - e- = 15 – 18 = -3

Quick Rehash… e- are found in shells outside the nucleus atoms are stable when: 1) number of protons and electrons are equal 1) number of and are equal 2) when the 2) when the valence shell is full is atoms will either atoms will either gain or lose valence electrons in order to have a full outer shell atoms will either gain or lose valence electrons in order to have a or valence electrons in order to have a outer shell valence shells hold up to 8 electrons, except for the valence shells hold up to valence shells hold up to 8 electrons, except for the first shell, which only holds valence shells hold up to 8 electrons valence shells hold up to 8 electrons, except for the first shell, which only holds 2 electrons. , which only holds .

12 protons How many electrons are needed to be neutral?

12 protons 2 electrons

12 protons 10 electrons

STABLE! 12 protons 12 electrons Total charge = 0

12 protons 10 electrons Total charge = p+ - e- = 12 – 10 = +2

STABLE! 12 protons 10 electrons Total charge = p+ - e- = 12 – 10 = +2

Calculating Charge of an Ion #p+ - #e- = ionic charge Atom of chlorine: 17 p+ - 17 e- = 0 charge Ion of chlorine: 17 p+ - 18 e- = -1 charge Atom of nitrogen: 7 p+ - 7 e- = 0 charge Ion of nitrogen: 7 p+ - 10 e- = -3 charge Atom of strontium: 38 p+ - 38 e- = 0 charge Ion of strontium: 38 p+ - 36 e- = +2 charge

Did you get it? For the following list of elements give the: number of valence electrons in the neutral element, the charge of the ion, the name of the ion, and the element’s nearest noble gas. a) iodine 7, -1, iodide, Xe b) aluminum 3, +3, aluminum ion, Ne c) phosphorus 5, -3, phosphide, Ar d) barium 2, +2, barium, Xe

Classification of Compounds Below is a flow chart for the classification of inorganic compounds.

Types of Compounds Ionic Compound : Formed from ions MUST HAVE A METAL!!!!!!! Examples: NaI W(NO3)3 Fe2S3 Non-examples: CO2 P2O5 XeF6

Types of Compounds Molecular Compound : NOT formed from ions MUST HAVE ONLY NON-METALS!! Examples: SO3 C6H12O6 H2O Non-examples: K2SO4 PtCl2 Sn(CO3)2