UNIT I - Safety & The Tools of Science
1
I. Laboratory Equipment
A. Things on a Ring Stand
OBJECT
PURPOSE
PICTURE
OBJECT
PURPOSE
Metal
Ring
To support wire
gauze or clay
triangle & hold
object above
burner
Funnel
Stand
To support a
funnel so a
beaker or other
container may be
placed under it
Test
Tube
Clamp
To hold a test
tube securely on
a ring stand
Wire
Gauze
Placed on a
metal ring.
Supports beaker
or other object
over burner.
Ring
Stand
To serve as a
base for holding
rings, Bunsen
burners, funnel
stands, etc.
Clay
Triangle
Placed on metal
ring. Supports
crucible over
burner
PICTURE
B. Objects Used to Manipulate Things
OBJECT
PURPOSE
Scoopula
To transfer
granular
solids from a
container to
another area.
Also good for
pulverizing
solids.
PICTURE
side
OBJECT
PURPOSE
Crucible
Tongs
To grab and
move a hot
crucible from
one area to
another.
view
To transfer
small amounts
of granular
solids.
Beral
(plastic)
Pipet
To transfer
small amounts
of liquid from
one area to
another.
Beaker
Tongs
To grab and
move a hot
beaker from
one area to
another.
Forceps
To grab and
move solid
objects.
Pipet
Bulb
To draw
liquids into a
pipet.
NEVER USE
YOUR
MOUTH!!!
Volumetric
Pipet
To measusre
out a specific
volume of a
liquid.
NEVER USE
YOUR
MOUTH!!
10 mL
Microspatula
PICTURE
UNIT I - Safety & The Tools of Science
2
C. Containers - NOTE: None of these are used for measurement
OBJECT
PURPOSE
Erlenmeyer
Flask
Glass
container with
narrow neck.
Good for
holding and
heating
chemicals
Test Tube
Small glass
tube with one
open end.
Commonly
used for
observing
reactions.
Squeeze
Bottle
Holds
cleaning
solution,
reagent or
distilled water.
Used to rinse
glassware.
Reagent
Bottle
Glass
container used
to hold
reagents.
Comes in
many shapes
and sizes.
PICTURE
OBJECT
PURPOSE
Beaker
Glass
container with
wide neck.
Also good for
holding and
heating
chemicals..
DO NOT USE
TO MEASURE
LIQUID
VOLUMES!!
Crucible
Porcelain
container used
for high
temperature
heating.
VERY
FRAGILE.
Evaporating
Dish
Lidless
porcelain dish
used for high
temperature
heating.
VERY
FRAGILE.
Spot Plate
Plastic plate
with many
wells. Used to
perform many
reactions next
to each other
for easy
comparison.
PICTURE
D. Measuring Devices
OBJECT
PURPOSE
Thermometer
To measure
temperatures of
objects or
substances.
UNITS: oC
PICTURE
43.5oC
OBJECT
PURPOSE
Electronic
Balance
To measure the
masses of
substances.
UNITS: g
13.45 g
30
Graduated
Cylinder
To measure
volumes of
liquids.
UNITS: mL
PICTURE
20
Volumetric
Flask
10
A flask designed
to very
precisely
measure one
particular
volume of liquid
UNIT I - Safety & The Tools of Science
3
E. Miscellaneous other Items
OBJECT
PURPOSE
Safety
Goggles
Protects eyes
from damage.
REQUIRED IN
LAB AREA AT
ALL TIMES
UNLESS
SPECIFICALLY
TOLD BY
INSTRUCTOR.
Plastic
Apron
Protects torso
and legs from
damage.
Hot
Plate
To heat
substances in
glass or
porcelain
containers.
Stir Rod/
Stir Bar
PICTURE
Rod - Glass rod
used to stir
solutions
Bar - Magnetic
Bar used on
hot/stir plate
OBJECT
PURPOSE
Rubber
Tubing
Used to
transfer a
fluid (liquid
or gas) safely
from one
container to
another.
Bunsen
Burner
Used for
heating
substances.
Produces up
to 950oC
Stopper
Used to close
flasks and test
tubes.
Varieties
include
rubber and
cork.
Funnel
Used to help
transfer
liquids from
one container
to another.
Also used to
make a filter
with filter
paper
PICTURE
F. Clues for Equipment Crossword
ACROSS
5. Glass container used to hold chemicals. Its edges
are slanted.
6. A ________ triangle holds crucibles when they
Are being heated.
8. A stir ____ contains a magnet that is used to stir
solutions on a stir plate.
11. A fragile porcelain dish used for heating chemicals is called an ____________ dish.
12. This is used to measure temperature.
14. This is placed on a metal ring and is used to support a beaker placed over a burner.
18. Cork or rubber
19. If you don’t wear safety goggles, this part of
your body is in danger.
20. This type of tubing is used to connect a bunsen.
Burner to the gas outlet.
22. These are required in the lab at all times.
DOWN
1. Attaches to ring stand and supports
wire gauze or clay triangle.
2. Crucible _______ are used to move a
hot crucible.
3. This type of glass pipet has a big bulge
in the center.
4. Used to measure volumes of liquids.
7. Used for heating objects with flame.
8. An electronic _________ is used to
get the mass of objects.
9. _____ ______ rack.
10. Small, fragile container placed on a clay
triangle to heat chemicals
13. Erlenmeyer ________
15. This is used to grab small objects.
16. A glass stir _______.
17. We set beakers on _____ gauze to heat.
21. Solid, liquid, and _______.
UNIT I - Safety & The Tools of Science
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G. Laboratory Safety Highlights
1. Safety Video
2. Symbols you should know:
SYMBOL
MEANING
SYMBOL
MEANING
Flammable Solid
RED - Flammable Gas or Liquid
BLUE – Dangerous when wet
Poisonous
Strong Oxidizer
Radioactive
Corrosive
Strong Irritant
Biohazard
3. Other Safety Highlights from Past Experience
a. Never directly smell or taste anything in the lab – learn to waft if smell is needed.
b. Always listen to Teacher’s tips before the lab.
c. Always READ THE DIRECTIONS FIRST!!!!!
d. Stick to the lab directions. Unauthorized experiments = trouble.
4. MSDS Labels – “Material Safety Data Sheets” – rank chemicals in certain danger areas on
a scale from 1-4.
A. Flammability – 0 is nonflammable, 4 is very flammable
* remember, in order to burn, oxygen must also be present
B. Reactivity – 0 means it is very inert (doesn’t react with much), 4 is very reactive
C. Health – 0 is safe (NaCl is a 1), 4 is very dangerous
* remember, you should never eat things in the lab, even 0’s
UNIT I - Safety & The Tools of Science
5
II. Rules of Significant figures
- importance?
A. All digits 1-9 are significant
1) 45.1
2) 0.153
B. All zeros in a “sandwich” are significant
1) 105
2) 4053.01
C. All zeros that end a decimal fraction are significant
1) 5.430
2) 6.0100
D. All zeros in front of a fraction and not in a sandwich are not significant
1) 0.00501
2) 0.0005
E. All zeros at the end of a number greater than 10 not in a sandwich are not significant.
1) 100
2) 1010
3) 100.0
F. A “lined” zero (θ) is significant.
1) 1θ0

2) 10θ
Try the “Atlantic-Pacific” rule to remember:
- If the decimal point is Present, count from the Pacific side
- If the decimal point is Absent, count from the Atlantic side
S. How many significant figures are there in:
1) 45.6
6) 5000
3
1
2) 150
2
3) 0.055
2
4) 0.0306
3
5) 10,000.1
7) 30.1
3
8) 30.10
4
9) 400.00
5
10) 0.000051
6
2
UNIT I - Safety & The Tools of Science
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III. Multiplying and Dividing Significant Figures.

When multiplying and dividing measurements, the answer should have a number of significant figures equal to
the multiplicant with the least number of sig figs
For example:
36.2 x
4.3 = 155.66
2 sig figs
3 sig figs
155.66
Calculator
answer;
needs to be
rounded to
2 sig figs
Keep
these
2
digits
160
Final
Rounded
Answer
Drop
these
digits
T. Calculate the following. Make sure the answer has the correct number of sig figs.
3sf
1)
1sf
3 sf
4.11 x 5  2 0.55  20
5 sf
2)
4 sf
3 sf
5.00 x 5.00  25.0  25.0
1sf
1sf
3) 4.7152 x 3.446  16.24 85792  16.25 4) 6 x 6  3 6  40
3 sf
5)
3 sf
38.1 655  0.058167938  0.0582
4 sf
6)
4 sf
9.475 12.05  0.7863 07053  0.7863
S. Calculate the following.
3 sf
1)
3 sf
3)
3sf
3.65 x 5.01  18.2 865  18.3
3 sf
2)
3 sf
26.0 x 2.00  52.0  52.0
2 sf
4 sf
5) 4.0 381.3  0.010 490427  0.010
3 sf
0.0522 x 0.827  0.0431 694  0.0432
2 sf
4)
3 sf
5.2 x 20.0  10 4  1 0
3 sf
2 sf
6) 4.08 0.061  66. 8852459  67
UNIT I - Safety & The Tools of Science
7
IV. Adding and Subracting Significant Figures.

When adding and subtracting measurements, round your answer to the decimal place represented by the least
precise number – round it to the “worst” decimal place
For example:
Nearest 1’s digit
Nearest 0.01
Nearest 10’s digit
123
40.55
+ 270
123
40.55
+ 270
433.55
433.55
Keep this
T.
1)
0.03694
+ 0.0770
----------0.11394
2)
38.5
0.051
+ 100
-----------138.551
0.1139
S.
1)
0.450
+ 0.034 7
------------0.484 7
3)
100
4.3
14.6 2
+ 327.9
-----------346.8 2
3)
346.8
V. Dealing with units in calculations -
drop this
6.0098
- 2.51
-----------3.4998
3.50
2)
0.485
430
7 61.8
- 1 00
---------6 61.8
700
* the units are treated just like variables in algebra
A. Multiplying and Dividing
In algebra:
2y x 4y = 8y2
Similarly:
4.5 cm x 10.2 cm = 45.9 cm2  46 cm2
Also:
35.44 g
-----------------
= 6.56296 g/mL = 6.6 g/mL
5.4 mL
B. Adding and Subtracting - ALL UNITS MUST BE EXACTLY THE SAME!!!!
For example:
However:
3.5 cm + 4.2 cm + 7.1 cm = 14.8 cm
3.6 cm + 0.21 km + 450 mm = Not Possible
UNIT I - Safety & The Tools of Science
8
VI. Measurement Activity –
1) Measure the length and width of 4 tile squares on the lab floor to the nearest 0.001 m
2) Calculate the area of each square. Make sure to round the answer to the correct number of sig figs.
3) Add your four results to determine the total area of the big square made up by your 4 squares.
Square
Length
(m)
Width (m)
Area (m2)
1
2
3
4
Total Area
4) Measure the length and width of the big square formed by the 4 squares you selected.
Length
(m)
Width (m)
Area (m2)
Questions:
1) How do the area values for the big square compare between question #3 and #4?
The areas should be fairly similar, but not exactly the same.
How can that be? It’s the same square, isn’t it?
2) Why do you think a difference occurs?
Every time, you take a measurement, there is a range of error that each measurement takes on.
Every time you do a calculation with a measurement, the error increases as well.
3) Describe how the number of sig figs in a measurement relates to its precision.
The more sig figs a number has, the more precise the measurement is.
In the above example, using a more precise measuring device (more sig figs) should produce
less error. As a result, the total areas in #3 and #4 should be more similar with the more precise
measuring tool.
UNIT I - Safety & The Tools of Science
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VII. Scientific Notation

a method used to express extremely large numbers or extremely small numbers
base - must be greater than
or equal to 1 and less than 10


4.56 x 105
power
the number of sig figs in a number expressed in scientific notation corresponds to the number of sig figs in the
base number
Contest: How many molecules are there in 36.0 mL of water? _________________________________
S. How many sig figs in the following numbers?
1) 3.123 x 103
4
2) 5 x 1011
1
3) 4.010 x 10-11
4
T. Convert the following to scientific notation: - move the decimal point to the left or right until the base
number is between one and ten. Large numbers (#1 & #2) have positive exponents. Small numbers
(#3 & #4) have negative exponents. Make sure the base has the same number of sig figs as the
original number.
1) 47,000,000,000
4.7 x 1010
3) 0.0000000005
5 x 10-10
2) 2,600,000,000,000
2.6 x 1012
4) 0.0000001020
1.020 x 10-7
S. Convert the following to scientific notation:
1) 863,030,000,000,000
8.6303 x 1014
2) 953,000,000,000,000,000,000
9.53 x 1020
T. Convert the following to decimal notation:
3) 0.000000040101
4.0101 x 10-8
4) 0.00000000000000021
2.1 x 10-16
S. Convert the following to decimal notation:
1) 4 x 10-4
0.0004
1) 5.0 x 10-5
0.000050
2) 9.24 x 107
92,400,000
2) 6.73 x 108
673,000,000
3) 7.030 x 106
7,03θ,000
3) 8.923 x 10-10
0.000 000 000 8923
UNIT I - Safety & The Tools of Science
10
When using your calculator, the “EE” or “EXP” button is equivalent to “10 to the.....”
Example: 4 x 105 x 3.2 x 10-2 is entered:
4
EE
5
*
What do you get?
3
1.28 04
.
EE
2
1.28 04
(-)
2
1.28 E 04
=
or
12800
Either way, you must round the base to the correct number of sig figs: Answer: 1 x 104
S. Calculate the following. Make sure the answer has the correct number of sig figs.
1) (2.3 x 106)(4.2 x 10-11) =
9.7 x 10-5
2) (4.00 x 10-15)(3.0040 x 104) =
1.20 x 10-10
3)
8.5 x108
3x10  4
3 x 1012
8.05x10 5.9 x10 
11
5)
6)
4)
4.00 x10 15
6.22 x105
7)
43,000,0000.00071
10.240.000000234
1.3 x 1010
8)
5.0404x10 3.2x10 
7.020x10 6x10 
4 x 10-48
7
14
3.1x10
1.5 x 10-17
5.444x10 1.0001x10  4.22 x 10-36
2.43x10 5.3063x10 
8
23
10
30
6.43 x 10-21
22
10
5
40
UNIT I - Safety & The Tools of Science
11
VIII. Graphing - an important tool in scientific experiments
* independent variable - x-axis; variable whose values are determined before the experiment
* dependent variable - y-axis; variable whose values are measured during the experiment
S. In each of the following statements, declare what is the independent variable and the dependent variable.
1. In my experiment, I checked the temperature of my heating water every 5 minutes.
* independent variable - TIME
* dependent variable - TEMPERATURE
2. I wanted to see the relationship between the pressure and volume of a trapped gas, so I increased the
pressure on the gas 0.500 atm at a time and measured the volume at that pressure.
* independent variable - PRESSURE
directly proportional – as “x” increases, “y” increases
y  kx
OR
k
y
x
* dependent variable - VOLUME
inversely proportional – as “x” increases, “y” decreases
xy  k
OR
x
y
k
S. Graph each of the following sets of data. Make sure you correctly label the independent variable and dependent
variable. When the data points are plotted, draw a best-fit line and answer the question.
* best-fit line – a line that approximates a linear pattern shown in data
1. Volume of an Enclosed Gas vs. Temperature
Temp
( oC )
25
30
35
40
45
50
55
60
65
70
Volume
(mL)
10.0
11.7
13.4
15.0
16.7
18.4
20.1
21.7
23.4
25.1
a. Is the relationship linear? If so, draw a
best-fit line.
YES. See graph
2. Data From a Bike Trip
Time
(hrs)
0
1
2
3
4
5
6
7
8
Distance
(km)
0
12
23
33
42
50
56
60
62
a. Is the relationship linear? If so, draw a
best-fit line.
NO
UNIT I - Safety & The Tools of Science
12
b. Is the relationship directly proportional,
inversely proportional, or neither?
NEITHER. It is linear, but it does not intercept the origin
b. Is the relationship directly proportional,
inversely proportional, or neither?
NEITHER.
c. Calculate the slope of the line.
c. Approximate when the biker will reach
100 km.
m
y2  y1 11.7  10.0 1.7


 0.34
x2  x1
30  25
5
Hard to determine. No good pattern
to the data.
d. Use the slope-intercept formula to
find the equation for the line.
y  mx  b
10.0  0.3425  b
10.0  8.5  b
b  10.0  8.5  1.5
V  0.34T  1.5
e. Using the equation, what will the volume be at
95oC?
V  0.3495  1.5  32.3  1.5  33.8mL
3.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
93.4  0.34T  1.5
91.9  0.34T
270 o C  T
4. Rate of Decay for 238U at certain temperatures
Water Temperature Fluctuations - 1991
Month
f. Using the equation, at what temperature would
the volume be 93.4 mL?
Temperature
( oC )
3.8
0.9
1.1
2.5
5.2
10.1
15.5
19.0
18.5
15.5
9.2
5.8
Time (min)
1
2
3
4
5
6
7
8
9
a. When is the peak month for swimming? AUGUST
Number of Atoms
256
128
85
64
51
43
37
32
28
a. Is this a linear relationship? NO
b. Does this lake freeze over? Explain.
NO. The temperature never goes below zero
c. Is this a linear relationship? If not, is there
still a predictable pattern?
NO. Yes, there is a general pattern to the data
b. Is it directly or inversely
proportional (or neither)?INVERSELY
PROPORTIONAL
c. Write an equation that fits this relationship,
including a proportionality constant (k)
xy=k  (t)(Atoms)=256
d. How many atoms will be remaining after 2.5 minutes?
(2.5 min)(A)=256
A = 102 atoms
UNIT I - Safety & The Tools of Science
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UNIT I - Safety & The Tools of Science
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UNIT I - Safety & The Tools of Science
15
IX. The Scientific Method - “The great tragedy of science--the slaying of a beautiful hypothesis by an ugly fact.”
- Thomas Henry Huxley
A. Definitions
1. Pure Science - science for its own sake
* Einstein – discovered Theory of Relativity (E=mc2) which shows a relationship
between Energy and mass  i.e. mass can be converted into energy
2. Applied Science – science with practical application for society
* Oppenheimer – using the Theory of Relativity, found that samples of
Plutonium performed a fission chain reaction in which the mass
of the nuclei was changed into energy; if the reaction was contained
in a rigid steel casing, it could be used as a bomb
3. Technology – the products of applied science
4. Chemistry – the study of matter and energy
B. Scientific Method: five steps - uses controlled experimentation
1) Stating a problem
2) Researching the nature of the problem - assign variables (remember to determine independent
and dependent variables)
3) Forming a hypothesis (educated guess)
* phrased: “As the [independent variable] increases, the [dependent variable] _______”
4) Designing an experiment
5) Collecting data (a series of measurements; requires units ( oC, m, mL, etc.)
6) Using data to decide validity of hypothesis - forming a theory (hypothesis shown to be true
over repeated experiments)
* law – an indisputable fact shown in experiment
- example: “Newton’s Second Law: Force equals mass times acceleration (F = ma)”
C. Accuracy vs. Precision
1. Accuracy – how close a measurement is to the actual value
2. Precision – the reproducibility of a measurement
* Describe the following measurements:
Actual Value: 3.532 m
Trial 1
3.539m
Trial 2
3.530m
Trial 3
3.529m
Accurate and precise
Actual Value: 3.532 m
Trial 1
4.192m
Trial 2
0.035m
Trial 3
10.112m
Neither accurate nor precise
Actual Value: 3.532 m
Trial 1
4.523m
Trial 2
4.520m
Trial 3
4.529m
Precise, but not accurate
(perhaps the measuring
tool is flawed)
* Why is it not possible to be accurate but not precise with measurements?
measurements can’t all be close to an accepted value, but be different from each other
UNIT I - Safety & The Tools of Science
16
D. Observation vs. Inference
1. Observation – something seen, heard, etc. – indisputable
* types of observations: qualitative (no measurement), quantitative(measurement)
2. Inference – an attempt to explain the cause of an observation; can be disputed.
S. Label the following as inference(I), qualitative observation(QLO), or quantitative observation(QNO)
I
1. From his scratching, that dog must have fleas.
QNO
QLO 3. The food smelled like sulfur.
I
5. She is crying, so she must be hungry.
QLO
7. The box is heavier than me.
QLO
9. The fish had blue-green gills.
I
11. Since the street is wet, it must have rained.
I
QNO
I
QLO
2. The fish weighed 1.75 pounds.
4. The food must have rotted.
6. The hat’s size is 7 3/4.
8. The box must be full of bricks.
10. The street is wet.
???? 12. “Boy is it hot!
It must be 95o out!”
E. Pre-Lab Observations
1. Observe a sugar cube dissolving in water. Note all the conditions under which this happened.
* these are called variables.
2. Choose one variable whose effect you will test on the dissolving time of a sugar cube.
a. Which one is the dependent variable? ____________________________
b. Which one is the independent variable? __________________________
3. Design an experiment which will test this relationship. Make sure to do the following:
a. Devise a hypothesis  “As the (ind. var.) (increases/decreases), the (dep. var.) (increases/decreases)
b. List any equipment needed to perform the experiment
c. Devise a detailed, step-by-step procedure you will follow.
d. Set up a data table that you will fill in when you do the experiment.
UNIT I - Safety & The Tools of Science
17
X. Systeme’ Internationale (SI system) – developed and adopted in 1960; has seven base units; five are shown on
table below (Ampere and Candela aren’t used in Chemistry)
A. Metric System
- Metric System devised in 1798 in Paris, FRA
- Metric System Treaty (1875) – adopted by all industrialized nations (inc. USA)
* by 1900, only British Commonwealth and USA didn’t use metric
* late 1960’s, early 1970’s, Commonwealth adopts
- Metric Conversion Act (1975) – USA will be under complete metric system by 1985
- Other non-metric countries (only 2)?
B. Units used - SI Base Units; adding a prefix modifies the unit
* How long is a meter (m)?
centimeter (cm)?
Unit
kilometer (km)?
Abbreviation Quantity
meter
gram
second
mole
Kelvin
m
g
s
mol
K
length
mass
time
number of items
temperature
C. Dimensional Analysis - a system used to solve any problem requiring proportional reasoning
* requires a known value and an equivalency
* example: I know 1m = 1000mm. How many meters are equivalent to 2430mm?
1. Write down the known value.
2. Set up your conversion factor.
3. Match units on the bottom of the conversion
factor with the known value.
4. Put the units desired on the top.
5. Place the known equivalency into the conversion factor.
6. Simplify.
2430mm
2430mm x _________
2430mm x _________
mm
2430mm x
m
mm
2430mm x
1
m
1000 mm
2430 mm x
1 m = 2.43 m
1000 mm
T. 1) 3.54 x 106 nm = ? m
2) 4500 kg = ? mg
10 6 mg
4500kg 
 4.5 x10 9 mg
1kg
1m
3.54 x10 nm  9
 0.00354m
10 nm
6
*When using the scale of metric prefixes on p. 18, the larger unit (higher up on the scale) gets a “1” next to it,
regardless of whether it’s on the top or bottom of the conversion factor. The smaller unit gets a power of 10 that
corresponds to the number of steps from the larger to smaller unit. In T #1, the 10 9 was on the bottom, so we
divided by that number, in T#2, the 106 is on the top, so we multiply by that number.
3) Given: 1km = 0.6214mi
4) Given: $1.00 = 4.87 tuttles and 1 tuttle = 15 crowns
How many kilometers is it from Holland to
If you travel to Tuttleland with $150 in your
Detroit? (186 miles)
pocket, how many crowns can you get?
186mi 
1km
 299km
0.6214mi
$150 
4.87Tuttles 15crowns

 10,957.5Crowns
$1
1Tuttle
*When given a conversion factor directly, as in #3 and #4 above, simply copy the numbers into their appropriate
places on the conversion factor
UNIT I - Safety & The Tools of Science
18
Giga- (G-)
Mega- (M-)
kilo- (k-)
DEFINITIONS
1 ton = 2000 lbs
16 oz = 1 lb
1 gal = 4 qts
1 foot = 12 in
APPROXIMATIONS
1 inch = 2.54 cm
1 liter = 1.06 qts
1 km = 0.6214 mi
1 kg = 2.2046 lbs
(base)
deci- (d-)
centi- (c-)
milli- (m-)
micro- (u-)
nano- (n-)
pico- (p-)
S. Complete the following conversions.
2) 3.71 x 10-11 km = ? nm
1) 78.0cm = ? um
78.0cm 
10 4 um
 78 ,000um
1cm
3.71x10 11 km 
3) 450g = ? kg
450 g 
4) 65.1 ms = ? s
1kg
 0.45kg
10 3 g
65.1ms 
3
10 mg
 30 0mg
1g
3.54 x10 7 um 
7) 5.66 inches = ? cm
5.66in 
1s
 0.0651s
10 3 ms
6) 3.45 x 107 um = ? km
5) 3.00g = ? mg
3.00 g 
1012 nm
 37.1nm
1km
1km
 0.0345km
10 9 um
8) 355 mL = ? qts
2.54cm
 14.4cm
1in
355mL 
1L
1.06qts

 0.376qts
3
1L
10 mL
D. Combined Units - treated in many ways like variables in algebra
* we’ll use rectangular stuff for simplicity
2.61 cm
1.1 cm
3.3 cm
3.55 cm
2.1 cm
A = lw = (3.55cm)(2.61cm) = 9.27cm2
NOTE: 1 L = 1 dm3
V = lwh = (1.1cm)(2.1cm)(3.3cm) = 7.6 cm3
1 mL = 1 cm3