The Nature of Science

1
The Nature of Science
I. The Methods of Science
-a _________ is a ______ used to help you
________ something, often something in a
________ _____
mnemonic
device
remember
particular
order
My
Very
Energetic
Mother
Just
Served
Us
Nine
Pizzas
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Kids
Play
Chess
On
Fat
Green
Stools
Kingdom
Phylum
Class
Order
Family
Genus
Species
2
The Nature of Science
I. The Methods of Science
My
Cat
Died
Drinking
Hot
Kool-Aid
meter
milli-
centi-
deci-
deka-
hecta-
kilo-
liter
gram
meter
milli-
centi-
deci-
deka-
hecta-
kilo-
liter
Mega-
Giga-
nano-
pico-
gram
0.1
0.01
0.001
1 x 10-9
1 x 10-12
10
100
1000
1 x 106
1 x 109
3
The Nature of Science
I. The Methods of Science
-unit cancellation
Multiply the Fractions
1
1 4
3 7
3 28
4 1
1 4
1 1
x

x


1
1
1
1
1
5 8
4 15
1 6
10 1
1 10
1 1
x

x


1
2
3
1
Reciprocal
1
3 2
2 3
1 1
x


1
1
Reciprocal
4
The Nature of Science
I. The Methods of Science
-unit cancellation
How many hectoliters in a deciliter?
1 dL
1 L
1 hL
x
x

0.001 hL
1
10 dL
100 L
How many microliters in a dekaliter?
1 dkL
10 L
1 x 106 µL
x
x

1 x 107 µL
1
1 dkL
1 L
5
The Nature of Science
I. The Methods of Science
-unit cancellation
How many megameters in 100 centimeters?
100 cm
1 m
1 Mm
x
x

1 x 10-6 Mm
1
100 cm
1 x 106 m
How many picograms in 1000 kilograms?
1000 kg
1000 g
1 x 1012 pg
x
x

1 x 1018 pg
1
1 kg
1 g
6
The Nature of Science
I. The Methods of Science
-unit cancellation
How many milliliters in 10 microliters?
10 µm
1 m
1000 mm
x
x

1 x 10-2 or 0.01 mm
1
1 x 106 µm
1 m
How many nanometers in 0.0001 Gigameters?
1 x 10-4 Gm
1 x 109 m
1 x 109 nm
x
x

1 x 1014 nm
1
1 Gm
1 m
7
The Nature of Science
II. Standards of Measurement
-the ___________ ______ of _____, or __, is
founded on _____ ____ _____, which ______ be
______ _____, and are ___ _______ from _____
_____
International
System
units
SI
seven
base
units
cannot
broken
down
not
derived
other
units
SI base units
http//physics.nist.gov/cuu/Units/units.html
8
The Nature of Science
II. Standards of Measurement
-other __ _____ are _______ _____, which are
________ by _________ _______ __ _____, and can
be _______ _____ into __ ____ _____
SI
units
derived
units
obtained
combining
different
SI
units
broken
down
SI
base
units
square meter
m2
Area
m2
cubic meter
Volume
m3
m3
m/s
Velocity
meter per second
m/s
N
kgm/s2
Newton
Force, Weight
P
N/m2
N/m2
Pressure
Pascal
Joule
J
Energy, Work
Nm
kgm2/s2
Watt
W
Power
J/s
kgm2/s3
9
The Nature of Science
II. Standards of Measurement
-_______ _____ might be ____________ of _____
____ ___ ____ ____, or a __________ of ____ ____
_____ and other _______ _____
derived
units
combinations
more
than
base
unit
one
combination
both
base
units
derived
units
http//physics.nist.gov/cuu/Units/SIdiagram.html
10
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
1. Hypothesis
How can the density of an unknown metal be
determined?
2. Prediction
3. Gather Data
A. Safety
Always use ordinary caution when using
electrically-powered laboratory devices like the
electronic top-loading balance. Also use
ordinary caution when using laboratory glassware.
Be sure to report any breakages immediately and
police the area.
11
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL, being
sure to read the bottom of the meniscus.
12
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL, being
sure to read the bottom of the meniscus.
13
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL, being
sure to read the bottom of the meniscus.
meniscus
14
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL.
2. Mass a dry sample of mystery metal on the
top-loading electronic balance. Record mass
to nearest tenth gram.
15
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL.
2. Mass a dry sample of mystery metal on the
top-loading electronic balance. Record mass
to nearest tenth gram.
3. Carefully slide the sample of mystery metal
down the side of the graduated cylinder
while holding the cylinder at an angle.
Avoid dropping the sample to protect the glass
of the cylinder and prevent splashing of the
water out of the cylinder. Record the final
volume to nearest tenth mL.
16
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
3. Gather Data
B. Procedure
1. Obtain a 25-mL graduated cylinder. Fill
about half full of water, and record the
initial volume to nearest tenth mL.
meniscus
2. Mass a dry sample of mystery metal on the
top-loading electronic balance. Record mass
to nearest tenth gram.
3. Carefully slide the sample of mystery metal
down the side of the graduated cylinder
while holding the cylinder at an angle.
Avoid dropping the sample to protect the glass
of the cylinder and prevent splashing of the
water out of the cylinder. Record the final
volume to nearest tenth mL.
17
The Nature of Science
II. Standards of Measurement
A. Measuring Matter
-Mystery Metal Density Lab
4. Analyze Data
-calculate the density to the appropriate number
of significant digits
3 significant digits
10.3 g

d

6.0588235

6.1 g/mL
1.7 mL
2 significant digits
-use the Periodic Table to determine the identity
of the Mystery Metal, based on its calculated
density
2 significant digits
5. Draw Conclusions
How can the density of an unknown metal be
determined? _____________________________________
________________________________