Today in class we continued learning about polarity and nonpolarity

• MOLECULAR AND INTERMOLECULAR BONDS
Intermolecular means the bonds outside molecules
- Intramolecular means bonds inside molecules

• Polarity is the result of intermolecular bonds
• Most bonds are electrostatic:

1. LONDON DISPURSION FORCE (L.D.F)
- Experienced by all molecules
- Result of electrons pushing on each other
- Weakest of all forces

- As the number of electrons increase L.D.F increases

- Comparison between the atoms Aluminum and Argon
Q:Which molecule will have a longer l.d.f?
A: Argon because it’s got more electrons. Which ever has more electrons experiences a longer LDF
- As the number of electrons increase L.D.F increases.



2. Dipole- Dipole
- Dipoles are partial separation of charges
- L.D.F is a type of temporary dipole
- Why is it a temporary dipole? Because electrons are always moving. Electrons always moving they don’t necessarily have to be in the same place.
- Some molecules have a permanent dipole
- These are polar molecules
- Polarity is determined by electrons affinity (how much an atom wants electrons)
- Electrons affinity is called electronegativity
- Electronegativity is highest on the top right and lowest on the bottom left


- Electronegativity is highest on the top right and lowest on the bottom left.
- A bond between two atoms/molecules with different electronegativities results in a dipole-dipole bond.

• Whats a dipole dipole strength between the two molecules Cl -Cl? None! Because none of them are polar
• Polar= dipole dipole
EXAMPLES: which bonds will result in a dipole-dipole force?

1.H-Clyes
2. O-Hyes
3. F-F No
4. O-Cl yes
5. I-Br yes

Are the following compounds polar or nonpolar?
1. CHCl3polar
2. 2. BI2Brpolar
3. C2H4non polar
4. C2H2Cl2non polar

DIPOLE DIPOLE FORCES ARE WEAK VERSIONS OF IONIC BONDS
COMPOUND Boiling Point Number of electrons
N2 -196 degrees celcius 14
O2 -183 16
NO -152 15
ICL 97 70
Br2 59 70

homework: questions 1 & 2 on worksheet

Today in class we learned about the polar and non polar solvents

Polar and non-polar solvents

• Polar substances have an unequal distribution of changes.
DRAW IMAGE



• Non- polar substance have equal change distribuation
DRAW IMAGE

and we did a lab - the objective was to determine if Glycerin is Polar or non-polar.
after mixing the test tubes, we noticed that the solvents water sugar- after mixing hte two dissolved. also the salt. some of the test tubes changed colors, for ex. iodine and the paint thinner. also after mixing iodine and water: it just changed colors from clear to brown, and it did not dissolve.

in the end we have conconluded that glycerin is polar because it mixed with water which is also a polar substance.
non polar can only react with non polar.
homework: FINISH THE LAB

April 12, 2010

Electrical conductivity in solutions requires charged ions to be transferred.
Ionic solutions dissociate, or form ions so they always conduct
NaCl(s)- Na(aq) + Cl(aq)
Molecular substances do not (usually) dissociate.
C12 H22 O11 h2o- C12 H22 O11 (aq)
BaCl2 (s) h2oBa(aq)+2 +2Cl- (aq)
CH3COOHCH3COO- +H+
96% 4%

Follow the chart to determine conductivity
Is it a metal if yes it is conductive

Homework:

1) Al (s)
2) H2so4(aq)
3) I2(s)
4) Br2(1)
5) Mg(OH)2(aq)
6) CH4(g)
7) PCL3(1)
8) ZnBr2(s)
9) NH3(aq)
10) Cr(NO3)2
11) H2O2
12) Cu3(PO4)2

In the beginning of class,we marked and went over 5-1 and 6-4.
We reviewed how to do lewis dot diagrams.

Covalent bonds
-electrons shared between non
- To draw lewis dot diagrams
1. Total all valence e- in all atoms
2. Identify the element that can form the most bonds. this will be the central
atom.
3. Draw bonds between atoms as a line. This represents 2 e-.
4. Any e- not part of a bond are lone pairs around the atom
5. Check to make sure each atom has a full octet.exception for hydrogen it has
two.
Mr. Doktor did a demonstration and showed a piece of sodium.It had a shiny finish to it. it has a high melting point. He put the piece of sodium into a glass filled with hydrogen.He tried to accomplish an explosion.
.

March 25

In the beginning of class,we marked and went over 5-1 and 6-4.
We reviewed how to do lewis dot diagrams.

Covalent bonds

• Electrons shared between non-metals


• To draw lewis dot diagrams

1. Total all valence e- in all atoms

Kristina Ravalo
Mr.Doktor
Chemistry 11
Block E
March. 23, 2010

Q: isotopes are used for in medicine? A:they give off radiation

ATOMS & IONS
• Atoms are electrically neutral
• # of protons= # of electrons
• Ions have different number of protons and electrons
• Ions can be either positive (lost e-) or negative (extre e-)
• Metals will be positive and non metals will be negative
• In order for something to be positive, it needs to lose electrons.
• If it’s negative it’s gaining electrons
• Cation= positive ion
• Anion= negative ion

Examples:
Determine how many electrons each of the ions have. What type of ion are they? (cation or anion)?
Ca2+  lose 2e- it is a CATION
Ag+ lose 1e- it is a CATION
F-  gains 1e- it is an ANION
H- gains an e- it is an ANION
H+ loses an e- it is a CATION
N3-  gains 3e- it is an ANION

Examples:
Determine how many protons, neutrons and electrons the following substances have.
Protons: same number as atomic number
Neutrons: atomic mass minus protons
Electrons: atomic number and protons

76AS3- protons: 33
 Neutrons: 43
 Electrons: 36
201 AU+  protons: 79
 Neutrons: 122
 Electrons: 78
56FE 3+ protons: 26
Neutrons: 30
Electrons: 23


BOHR DIAGRAM FOR IONS
• Draw the energy level bohr diagram for the following ions:
-Ca 2+
8e-
8e-
2e-
Ca

-Li+
4-
2-
Li

F-
8-
2-

O2-
8e-
8e-
2e-

P3-
8e-
8e-
2e-

CHEMICAL BONDS
• A bond is an electrostatic attraction between particles
• Bonds occur as elements try to achieve noble gas electron configuration
- Noble gases (usually) do not form compounds or bonds
- In noble gases the outermost energy level have stable octets
• Metals lose electrons (oxidize)
• Non metals gain electrons (reduced)




LEWIS DOT STRUCTURE
• Atoms can be represented by dot diagrams
- - Dots represent electrons
- Only valence level electrons are shown
• Write the atomic symbol for the atom
-This represents the nucleus and filled inner electron levels
• One dot is used to represent outer energy level electrons
-One e- is placed in each orbital before any pairing occurs
- Beginning with the 5th e-, pairing can occur up to a maximum of 8e-

Ex. Draw the lewis dot diagram for the following atoms:
- Nitrogen
- Fluorine
- Oxygen
- Calcium
- Lithium
- Hydrogen



LEWIS DOT STRUCTURE
• Atoms can be represented by dot diagrams
- - Dots represent electrons
- Only valence level electrons are shown
• Write the atomic symbol for the atom
-This represents the nucleus and filled inner electron levels
• One dot is used to represent outer energy level electrons
-One e- is placed in each orbital before any pairing occurs
- Beginning with the 5th e-, pairing can occur up to a maximum of 8e-

Ex. Draw the lewis dot diagram for the following atoms:
- Nitrogen
- Fluorine
- Oxygen
- Calcium
- Lithium
- Hydrogen

IONIC BONDS
• Electrons are transferred from metal to nonmetal
- No dots are shown on metal
• ‘charged’ species is written in brackets
• Example: sodium chloride
Na Cl

EX: DRAW THE LEWIS DOT DIAGRAM FOR
- LITHIUM FLUORIDE
- CALCIUM CHLORIDE

Thompson experimented with ELECTRONS.

8e-
8e-
2e-
Nucleus

Increase in voltage = increase in energy

High voltage power source
1. Hydrogen – spectrum lines are very simple
2. Different elements on periodic table have different colors
3. Colors help determine what elements are in a star for example

Emission Spectra

• Each element gives off a specific colour of light
• These are known as emission spectra
-unique to each element
• If electrons absorb energy they can be bumped to a higher level
• When they fall to a lower level they release energy as light
• Each element has its OWN combination of colours

Atomic Structure

• Atoms are made up of parts called SUBATOMIC particles
• Protons (positive)
• Neutrons (neutral)
• Electrons (negative)
• Electrons have to exist in energy levels

PARTICLE MASS
(multiples of proton) CHARGE
(elementary charges) LOCATION
PROTON 1 +1 Nucleus
NEUTRON 1 0 Nucleus
ELECTRON 1/1837 -1 Outside




Atomic Number

• Atomic Number: number of protons
• Diagram of the element Titanium (Labels: atomic number, symbol, atomic mass, and ion charges)

Isotopes

• The number of protons determine the type of element
• Changing the number of neutrons changes the ISOTOPE of the element
• All isotopes have the same chemical properties
• The nuclei of the three isotopes of hydrogen
Protium Deuterium Tritium
*1 proton *1 proton *1 proton
*1 neutron *2 neutrons

Mass Number

• Mass number is total of protons and neutrons
• Symbol give is A
• Different isotopes have different masses (ex. Helium)
• Mass Number = Atomic Number + Number of Neutrons
A = Z+N
• Examples:
How many protons and neutrons are in each of the elements?
Lithium Titanium Silver
Protons = 3 Protons = 22 Protons = 47
Neutrons = 4 Neutrons = 26 Neutrons = 61

Complete the table
ISOTOPE MASS # ATOMIC # # OF PROTONS # OF NEUTRONS
OS
Osmium 190 76 76 115
Zn
Zinc 65 30 30 35
C
Carbon 14 6 6 8
H
Hydrogen 2 1 1 1

HOMEWORK: 1Periodic Table Assignment & 2Atomic Theory: Isotopes (in the booklet)