Announcements

1
Announcements

• Questions?
• Book problem solutions chem131
• Handouts and Blackboard
• Envelopes
• Notecard scores and attendance
• Pictures

2
Density and the Problem Solving Method

• You accidentally break a thermometer and find
  that the mercury that comes out has a mass of
  0.34 g. What volume of mercury was contained in
  the thermometer (The density of mercury is 13.6
  g/mL.)
• What do you want? (units)
• What do you know? (facts and relationships)
• Set up and solve.
• Answer correct method not!
• Why does this matter?

3
Percentage and the Problem Solving Method

• An average adult breathes about 8.50 x 103 L of
  air per day. The concentration of lead in highly
  polluted urban air is 7.0 ? 10-6 g of lead per
  one m3 of air. Assume that 75 of the lead is
  present as particles less than 1.0 ? 10-6 m in
  diameter, and that 50 of the particles below
  that size are retained in the lungs. Calculate
  the mass of lead absorbed in this manner in one
  year by an average adult living in this
  environment.

Setup percentages as relationships Answer 8.1
10-3 g Pb absorbed / year
4
ATOMS, MOLECULES AND IONS
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Daltons Atomic Theory

• Law of conservation of mass
• Symbolic representations
• Molecular level representations
• Law of constant composition
• Law of multiple proportions

Group Activity
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Using Daltons Atomic Theory

• You have been given a box containing four
  molecules of phosphorus trifluoride.
• Draw a molecular representation of the four
  molecules in box a.
• You perform a chemical reaction and convert all
  of your molecules of phosphorus trifluoride into
  elemental phosphorous and elemental fluorine.
  Draw a molecular-level representation of these
  atoms (or molecules) in box b.
• You performed a chemical reaction and your
  molecules have turned in to something other than
  the pure elements. According to Daltons atomic
  theory, what is a possible product of this
  reaction?
• Each person should make their own prediction then
  the group should decide if it is valid according
  to Dalton.
• This is your one chance to express your
  creativity the molecules that you make do not
  have to be molecules that you would find in
  nature!

Group Activity
7
Atomic Structure

• What is an atom?
• Subatomic particles
• electron
• proton
• neutron
• Atomic structure
• What makes atoms unique?

8
Representing atoms
X
A
Z
Group Activity
9
Notecard Questions

• Work should be your own.
• Discussion okay.
• Time limited!
• Pass them to the center then down to the front.

Notecard Question
10
Density and the Problem Solving Method

• An atom has 11 electrons and 12 neutrons.
  Write the symbol, including mass number and
  atomic number, for this element.

2 minutes
Notecard Question
11
Course Business

• Envelopes
• Seating assignments

12
The Periodic Table Information Chemistrys Best
Cheat Sheet

• Always have
• Some things must be memorized
• Element names and forms (monatomic, diatomic,
  polyatomic, infinite)
• Metals vs. metalloids vs. nonmetals
• States of matter

13
(No Transcript)
14
The Periodic Table Information Chemistrys Best
Cheat Sheet

• Atomic Mass, structure
• Type of compound formed
• Ionic charges
• Properties / reactivity

45 Rh 102.9055
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Molecular Compounds

• Elemental composition
• Number of atoms
• State of matter
• Formula
• Molecular formula

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Naming Molecular Compounds

• prefix-element prefix-elementIDETABLE 2.4
• CCl4
• dinitrogen tetroxide
• P4O10

17
The Periodic Table Information Chemistrys Best
Cheat Sheet

• Always have
• Some things must be memorized
• Element names
• Metals vs. metalloids vs. nonmetals
• States of matter

Group Activity