Bell Work p.263 CO2 H2S Draw these Lewis Structures and name the shape PCl3 CO2 H2S

Name their shapes and bond angles Trig. pyramidal PCl3 CO2 H2S Linear Bent

Today Molecule shapes and angles review Electronegativity (EN) Polarity

Draw Lewis structures and name the shape (p. 263) PCl5 HI AlCl3 SF6 Trig. bipyramidal Linear I Trig. planar octahedral

I e-! An element’s ability to attract electrons in a chemical bond p. 194 Electronegativity (EN)- what is it? Write YOUR definition of EN on your board An element’s ability to attract electrons in a chemical bond

Where’s the e- party? http://www.youtube.com/watch?v=QqjcCvzWwww

Why do Ionic bonds transfer e- and Covalent bonds share? If big difference (>1.7) in EN= ionic Li= 0.98 F= 3.98 3.98-0.98= 3.0 IONIC Li F F has enough “power” to take an e- from Li

Why do Ionic bonds transfer and Covalent bonds share? If small difference (<0.4) in EN= covalent (N2) N=3.04 3.04-3.04=0 Neither N has enough power to take an e-, so they share

What if they share e- , but unequally? If medium difference (0.4-1.7) in EN= POLAR covalent H= 2.20 Cl= 3.16 3.16-2.20= 0.96 + - +pole -pole

Electronegativity (Recap) big difference (>1.7) in EN= ionic small difference (<0.4) in EN= covalent medium difference (0.4-1.7) in EN= POLAR covalent Difference in EN Range Bond Type Big >1.7 Ionic Medium 0.4-1.7 Polar covalent Small <0.4 Covalent

Calculate Diff. in EN and find if ionic, polar covalent or non-polar covalent (PT on p. 265) OH F2 LiCl H2 3.44-2.20=1.24 Polar covalent 3.98-3.98=0 non-polar covalent 3.16-0.98= 2.18 ionic 2.20-2.20=0 non-polar covalent

How can we determine whether a molecule is polar or nonpolar? Electronegativity ______________ And the ________________ POLAR Molecules are _____________ And Nonpolar Molecules are ______________ Shape Asymmetric Symmetric

POLAR= asymmetrical Non-polar=symmetrical

Draw it and determine P or NP? NH3 CCl4 H2S PCl3 Br2

Exit Slip What does it mean when we say a molecule is polar?

Bellwork Electronegativity (EN)= How strongly an atom attracts ________ in a bond. __________ is the most EN on the PT If one atom has a much higher EN, it will unequally share e- polar e- F

Linear 180o NP 107.3o P Bent 104.5o P Trig. planar 120o NP Shape Name Bond < P or NP Linear 180o NP Trig. pyramidal 107.3o P Bent 104.5o P Trig. planar 120o NP

Today Polarity Review Lewis structures Properties Bending Water lab How does soap work? What is surface tension?

Linear 180o NP 107.3o P Linear 180o P 109.5 NP Trig. pyramidal Shape Name Bond < P or NP Linear 180o NP Trig. pyramidal 107.3o P Linear 180o P Tetrahedral 109.5 NP

Draw it! P or NP? C2H4 CH3CH2CH3

H-H H-I C=O O=O H-F P-H F-F

Draw a Water Molecule (Lewis) Label the – and + poles

Water Balloons Hold your balloon about 1” away from a THIN stream of water Draw a picture of what happened, using a water molecule - - - - ?

Water is POLAR

Why does water “bead” together? Positive (+H) poles attract negative poles (-O)

Why does oil float on water? “Like dissolves Like” Polar dissolves in polar Non-polar dissolves in non-polar Oil, grease, fat= non-polar Water= polar

How does soap work? Article-”How does soap dissolve grease?” Lab- Petri dish with oil drops Beaker with soapy water Q-tip Article-”How does soap dissolve grease?” Read article, then write an explanation for how soap breaks up grease into smaller particles-(5 sentences)

Exit Slip Draw carbon tetrachloride, name its shape, bond angle and polar or non-polar