Unit 1 Loose Ends and
Test Review
Objective A
(remember, the objective refer to the Study Guides)
http://www.magazine-agent.com/officials-logic-problems/magazine
 Look at the following numbers. How easy
would it be to memorize this list and
regenerate it in a week or so on a quiz?
 1, 3, 5, 11, 21, 43, 85, 171, 341, 683, 1365,
2731, 5461, 10923, 21845
 Pretty hard? Pretty Easy? Why?
 Easy huh? OK, what’s the next
number in the sequence? How
about the next 5 numbers?
1, 3, 5, 11, 21, 43, 85, 171, 341, 683,
1365, 2731, 5461, 10923, 21845
http://www.antiqueradiomuseum.org/RR%20Rule%20Book%20for%20CMSP&P%20RR.jpg
 The numbers don’t seem to follow
any kind of pattern.
 But, what if you knew a rule? It
wouldn’t just be memorization then.
 OK, good point! The rule is:
You just wish it
was that EASY!




Start with 1.
Double and add 1.
Double and subtract 1.
And so on.
Learn HOW to do the problem;
don’t just memorize the answer!
http://familyfun.go.com/Resources/printable-previews/previews/beaver_memorygame_august2.jpg
Don’t
 Doesn’t “knowing the rule” make
the list easier to memorize?
 You don’t have to memorize a
bunch of unrelated numbers.
 IF YOU KNOW the rule, you can
generate the number list on the test
easily. Anytime! Anywhere!
Can you make sense out of
NONSENSE?
 Force
Hour
Upon
Neigh
 Koran
Force
Cis
Shun
 Heaven
Fodder
Count
 Ye
Brat
Anent
 Sago
Farce
Anew
 Figured it out yet?
The Gettysburg Address
http://www.old-picture.com/defining-moments/pictures/Abraham-Lincoln-Antietam-Battlefield.jpg
http://en.wikipedia.org/wiki/Gettysburg_Address
 “Four score and seven years ago our
fathers brought forth on this continent a
new nation, conceived in Liberty, and
dedicated to the proposition that all men
are created equal.”
Yes, Ms Rackley, I
know this was
Antietam, but it’s a
nice picture.
 Being able to look at
something new, and make
sense of it is an important
skill for the rest of this
course.
Objective A
http://www.tvgasm.com/newsgasm/Bill-nye.jpg
What
would
Bill Nye
do?
 In Chemistry, when we have
numbers, much of the time we do
one of three things:
 Multiple 2 x 3
 Divide 2 / 3
 Divide 3 / 2
 If you can figure out which
operation to do when, you can
actually solve the problem. That’s
our goal.
Answer: nothing because he just died.
Units TELL you the right
ANSWER!
 If your units don’t work
out right, your answer is
wrong.
 Don’t just ignore wrong
units. It is a big clue for
you.
 LISTEN to the units!
Qualitative and
Quantitative Data
 Qualitative (think quality)
 These are observations usually.
 It’s blue. It’s hot. It’s cool. It’s smells like rotten eggs.
 Remember to look for qualitative date when you do your lab
experiments.
 Quantitative (think quantity or amount)
 These are the numbers you measure.
 5.0 g of baking soda. 2L of diet Coke. 4.5 moles of CO2.
 Remember to record quantitative data in your lab notebook
when you do experiments too.
Objective C…Error
 We will discuss error primarily in our labs. Always
include a discussion of any errors that happened in
your experiment in your “Analysis of Data” section
of your lab report.
 What kind of errors can you have in your labs?
 Two kinds:
 Random
 Systematic
Objective C…Error
http://www.budapesthotels.com/sitepic/error_button.png
http://images.intomobile.com/wp-content/uploads/2009/06/easy-button.jpg
Easy Button
 Random errors are mistakes. You can
take care to reduce or eliminate random
errors. These usually come from being
unprepared (not reading the lab prior
to doing it), rushing to get done, and
careless errors (like forgetting to do a
step).
Error Button
 Systematic errors are errors that are
present in your system. You can’t do
anything about these. If your data is
precise, but not accurate this might
indicate that you had systemic error.
Objective d…Significant Figures
 When you take measurements in Chemistry class or in lab,
you have to worry about how many significant figures
(usually abbreviated as sig figs) you have.
 What are sig figs?
 All the digits you can read and the first one you can estimate.
Between 7.1 and 7.2, so record as 7.15. All 3 digits are significant,
because you read the first 2 and estimated the last 1.
Objective d…Significant Figures
http://www.freefoto.com/images/2000/98/2000_98_1---Number-Zero_web.jpg
Significant?
Maybe or
maybe not!
 However, if you didn’t measure it,
there are rules for figuring out
how many sig figs something has.
 RULE #1. All non-zero digits are
significant.
 So that means that the only thing
you have to determine is whether
or not the zeros are significant.
Objective d…Significant Figures
 Rules are in the study guide.
 2. Zeros between non zero digits are significant. So,
2.003 has 4 sig figs.
 3. Zeros at the end of a number AND to the right of
the decimal point are significant. So, 1.000 has 4 sig
figs.
 4. Zeros at the beginning of a number are never
significant. So, 0.00034 has 2 sig figs.
 5. Exact measurements or exact quantities have an
unlimited amount of sig figs. Example 1 hour = 60
min. “1” and “60” both have an unlimited number
of sig figs.
Objective d…Significant Figures
 Adding/Subtracting
 Answer cannot have more sig figs AFTER the decimal point than the
number with the lowest number.
 Ex: 2.1 + 2.22 + 2.345 = 6.665
 Answer can only have 1 digit after the decimal
 Correct answer = 6.7
 Multiplying/Dividing
 Answer cannot have more sig figs than the number with the lowest
number of sig figs.
 Ex: 2.22 x 2.345 = 5.2059
 2.22 has 3 sig figs and 2.345 has 4 sig figs. Answer can only have 3 sig
figs.
 Correct answer = 5.21
±1 sig figs off is usually OK. If answer should have 4
sig figs and you have 3, 4 or 5, I won’t mark it wrong.
Objective d…Significant Figures
http://www.tvguide.com/celebrities/stuart-scott/214001
 But isn’t 50 and 50.0 and 50.00
and even 50.000 the exact same
number?
50 ≠ 50?
Wha-haphappen?
 Maybe, outside of chemistry
class, but not in here.
 Let me explain.
Objective d…Significant Figures
 50 means that your measurement is somewhere
between 49 and 51.
 50.0 means that your measurement is
somewhere between 49.9 and 50.1
 50.00 means that your measurement is
somewhere between 49.99 and 50.01
 50.000 means that your measurement is
somewhere between 49.999 and 50.001
The more sig figs in your measurement, the more
confidence you have that it’s “exactly” 50 mL or g.
Objective f…Density
http://www.stevespanglerscience.com/img/cache/bcb9b8db117ee64376aedaf7af3595ca/sevenlayer-251908.jpg
Higher density layers on
the bottom and lower
density layers on the top.
Is oil more or less dense
than water?
D=m/V
Objective g…Ice Floats
http://www.dharma.org/ims/images/pi_ice_on_pond.jpg
 Why does ice float?
 Why is this a good
thing?
 Ice is actually kind of
strange. Actually water
is a very unique
compound.
 Most substances are
more dense as a solid
than they are as a
liquid.
 Ice is an exception.
Objective h: Measure your Kinetic
Energy: Take Your Temperature!
http://www.avogadro.co.uk/miscellany/t-and-p/thermometers.gif
 Kelvin temperature was defined to
be a measure of the kinetic energy of
the sample of matter. 0K is
ABSOLUTE zero.
 A sample of matter at 300K has twice
as much kinetic energy as a sample
of matter at 150K. Temperature is
directly proportional to kinetic
energy.
 You must remember how to convert
from °C to K and vice versa. It
WILL be on the test.
The End
What is next?
Unit 2: Chapter 5, 28, 13, and 14.
We will do ALL of Chapter 5, but only portions of the other 3 chapters.