Question of the Day How are ionic and covalent bonds different? 9-23

Explain the formation of compounds (ionic + covalent) and their resulting properties using bonding theories. Objective 9-23

Question of the Day 9-24 Get out your POE from yesterday (lab paper). Were there any substances that surprised you (there should probably be at least one)?

Explain the formation of compounds (ionic + covalent) and their resulting properties using bonding theories. Objective 9-24

E xplain Water # 1 Water # 2 Salt water Sugar water Vegetable Oil Names __________________ ________________________ Come up with an explanation for why the two water samples may have been so different. When ionic compounds are dissolved in water they break apart into ions what two ions is the salt break apart into (include charges)? We will come back to these two later leave them blank for now. Page 34 #s 1-8

My.hrw.com Page 34 #s 1-8 Allan Smith 15 Kamil Kolkowski 9 Natalie Gilbert Robert Riffel Justin Smigley 10 Ali Smith 11 Matthew Rivera 14 Alexandria Clowney 12 Vincent Farber 6 Ryan Freeman 13 Victoria Jurjevic 8 James Harkness 8 Kyle Watson 7 Mariangely Onativia 2 Thomas Sinner Nicole Deluca Kenneth Charlot 3 Evan McSwegan 4 Christopher Cayo 5 Elizabeth Buzzard 5

1 st period is all the way done with 1-8 but second period finished it for hwk and needs to go over it.

Covalent bonds can be __________ or ___________. Question of the Day 9-27

Compare and contrast different bond types that result in the formation of molecules and compounds. Objective 9-27

Nonpolar Covalent bond - bonding electrons are shared equally by bonded atoms Polar Covalent bond - bonding electrons are shared unequally by bonded atoms

Covalent bonds can be polar or nonpolar Ionic bonds Polar Covalent bonds Nonpolar Covalent bonds Transfer elecs. Share elecs.

What is the difference between polar and nonpolar covalent bonds? polar Moving in the ionic direction Atoms attract shared electrons unequally nonpolar Purely covalent Atoms attract shared electrons equally

The Fight for Electrons – bonding as a tug-of-war HH HBr TieCovalent Polar Covalent

NaCl Ionic The Fight for Electrons – bonding as a tug-of-war

Bonds are purely covalent when …

Quick Talk Neutron Ionic bond Mass number Octet rule Biosphere Valence electrons Atomic number Covalent bond Proton Biotic factor Penn State

Water contains __________ bonds. Question of the Day 9-28

Describe how the unique properties of water support life on Earth. Objective 9-28

READ pages AND complete #s 1-8 of the section review on page 44

Polarity – –When a molecule has an uneven distribution of charge (unequal electron sharing Water - –Oxygen doesn’t share the electrons equally with hydrogen –So if the oxygen pulls the electrons closer, the oxygen then becomes partially negative, and the hydrogen will become partially positive. –Draw a water molecule:

Hydrogen Bonding O H H (-) (+) O H H (-) (+) O H H (-) (+)

Bonds Hydrogen Bonds – –A hydrogen bond is the force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge. –Weak attraction between the partially negative oxygen and partially positive hydrogen –This is what gives water some VERY IMPORTANT qualities

Important Qualities of Water –Surface Tension: Created by hydrogen bonds – the water is able to resists force of objects -- water “sticks” to itself –Which is more dense, water or metal? Metal –Floating paper clip?!?! Why??? Metal, but paperclip floats b/c water is weakly bonded and those bonds are not breaking.

Molecule – group of atoms united by covalent bonds (molecules = molecular substance) FORMULAS Chemical-How many atoms of each element Structural - How atoms are bonded together