The document defines key concepts related to the metric system, including units of measurement for length, mass, temperature, and density, as well as the importance of significant figures and measurement techniques. It emphasizes the ease of conversion within the metric system, discusses prefixes like kilo- and centi-, and highlights differences between mass and weight. Additionally, the document outlines practical experiments for measuring and converting various metrics, underscoring their application in scientific contexts.

1. Learning Objectives
Define the International System of Units (measurement
system).
Define a unit of measurement and demonstrate the ability to
convert measurements.
Define length, temperature, time, volume, mass, density, and
concentration.
Define significant figures and describe measurement
techniques.
Introduction
Just like you and your friend communicate using the same
language, scientists all over the world need to use the same
language when reporting the measurements they make. This
language is called the metric system. In this lesson we will
cover the metric units for length, mass, density, volume and
temperature, and also discuss how to convert among them.
Metric Measurement
What do all of these words have in common: thermometer,
barometer, diameter, odometer and parameter? All of these
words end in
-meter
. You have probably heard this word before, but what does it
mean? Meter at the end of a word means

2. measure
. You use all kinds of measurements each day. How much sugar
is needed in the cookies you are baking? Will it be warm
enough to leave your jacket at home? How fast are you driving?
How much will a bag of apples cost? How much time will it
take you to get home from work?
The units of measure in the English and metric systems
Most Americans are taught the English or standard system of
measurement, but never get a good dose of the metric system.
Lucky for you, it is a much easier system to learn than the
English system because all the measurements are
base 10
- meaning that when you are converting from one to another,
you will always be multiplying or dividing by a multiple of
10
. This is much easier than trying to do calculations between
ounces and pounds, and feet and miles.
Because you may not be used to thinking metrically, it may take
a little practice using and working with the metric system
before you gain a better understanding of it and become more
fluent in the measurement language of scientists (and most non-
Americans). I challenge you to sprinkle a little more metric in
your life. Maybe read the milliliter measurement on your soda
can or glance at the kilometer reading on your speedometer.
Being able to picture metric quantities will really help with the
rest of this course.
Length

3. We are going to start with the units of length so we can get back
to this word meter that we started out with. The meter is the
basic unit of length in the metric system. A meter is a tiny bit
longer than a yard. For distances much longer than a meter, you
would add the prefix kilo- to make the measurement kilometer.
A kilometer is the metric version of our mile, even though it is
a bit shorter than our mile. A kilometer is equivalent to exactly
1,000 meters. Any unit that has the word kilo- in front of it is
equivalent to 1,000 units. You can attach the prefix kilo- to just
about anything. If something takes 1,000 seconds, it takes a
kilosecond. If a forest has 1,000 trees, it has a kilotree. You get
the idea.
The balance measures mass in grams.
For distances much shorter than a meter, we would use either a
centimeter or a millimeter. A centimeter is about the width of
your pinky. There are exactly 100 centimeters in a meter. In
fact, anything that has the prefix centi- is one-hundredth the
size of that base unit. This should be very easy to remember,
because there are 100 cents in a dollar. One cent is one-
hundredth of a dollar!
The last prefix you should be familiar with is milli-. There are
exactly 1,000 millimeters in a meter. Anything that has the
prefix milli- is 1,000th the size of its base unit. This one is a bit
more difficult to remember, but it is definitely the prefix you
would use the most in a chemistry class.
Mass

4. Next on our list of important metric quantities is mass. This is
one of the most important measurements a chemist makes. Mass
is how much of something you have, or the amount of matter in
an object. Do not confuse this with volume; volume is a derived
unit It is derived by multiplying the length times the width
times the height of an object. Mass is measured using a balance,
and the basic unit for mass is the gram. To give you an idea of
the relative size of a gram, the mass of a penny is about 2.50
grams.
Sometimes people get confused with the difference between
mass and weight. They end up being quite similar because
everything you and I do takes place on Earth. But, mass and
weight differ because mass is how much of something you have
and weight is the force of gravity on an object. Take a look at
this example. Both of these blocks have the same mass (one
kilogram, or 1,000 grams), but one is on Earth and the other is
on the moon. Because the Earth has more mass than the moon, it
is going to pull the block with more force. This is why things on
Earth have more weight than things on the moon, even though
both have the same mass. This may be difficult to imagine
because it is not like you are going to the moon on a daily basis
to check this out.
Pre-Lab Questions
1. The SI system unit for the amount of a substance
is_____________.
2. The International System of Units (SI) is
___________________________________________. (provide a
definition)
3. Convert 15.00oF to oC.

5. 4. Convert 5.00 miles to kilometers
5. A_______________ is the curve that forms between the
liquid and the surface of the container as the result of the
following properties of liquids: _______________________,
_________________, and _________________.
6. ____________________ is defined as mass per unit of
measure.
7. The definition of %
m/V
is ________________________. (provide the formula)
8. Explain why significant figures include only the certain
digits of a measurement.
9. When reading a graduated cylinder made of glass, one must
read the volume at eye level from the
_________________________ of the meniscus.
10. A volumetric flask contains 25.0 mL of a 14%
m/V
sugar solution. If 2.5 mL of this solution is added to 22.5 mL
of distilled water, what is the %
m/V
of the new solution. (use the formula from question 7 to
calculate this answer).
11. Calculate experimental error (aka percent error) using the
following data: the measured value equals 1.4 cm; the accepted
value equals 1.2 cm.
12. What is the volume of an irregularly shaped object that has

6. a mass 3.0 grams and a density of 6.0 g/mL
Procedure:
I.
Length Measurements
Materials you will need:
·
Metric ruler
·
CD or DVD
·
Key
·
Spoon
·
Fork
1. Gather the metric ruler, CD or DVD, key, spoon, and fork.
2. Look at the calibration marks on your ruler to determine the
degree of uncertainty and number of significant figures that can
be made when measuring objects with the ruler.
Note: Record every measurement you make with this ruler to the

7. same decimal place. Remember to do this any time you use this
ruler throughout the experiment.
1. Measure the length of each of the following objects (CD or
DVD, Key, Spoon, Fork) with the ruler in centimeters (cm) to
the correct level of precision and record in
Data Table 1.
2. Convert the measurements for each of the objects from
centimeters to millimeters and record in
Data Table 1
.
3. Convert the measurements for each of the objects from
millimeters to meters and record in
Data Table 1
.
II.
Temperature Measurements
Materials you will need:
·
Pyrex one-cup measuring cup
·
Thermometer (Fahrenheit OK, Celsius would be best)
·
Safety glasses
·
Potholder

8. ·
Plastic cup
·
Ice cubes
·
Tap water (hot and cold)
1. Gather the 1 cup Pyrex measuring cup, cup (plastic or
drinking), and thermometer.
Note: Your thermometer is probably going to be in Fahrenheit
scale, and you will have to convert to Celsius and Kelvin.
1. Look at the calibration marks on the thermometer to
determine the degree of uncertainty and number of significant
figures that can be made when measuring temperature.
Note: Record every measurement you make with this
thermometer to the same decimal place. Remember to do this
any time you use this measuring device throughout the
experiment.
1. Turn on the tap water to hot. Let the water run as hot as
possible for approximately 15 seconds.
2. Fill the 1-cup measuring cup to the 1/3 cup mark with hot tap
water.
3. Measure the temperature of the hot tap water with the
thermometer and convert to degrees Celsius (°C) to the correct
precision of the thermometer. Record the measurement in
Data Table 2
.

9. Note: When measuring the temperatures place the thermometer
into the water so that the silver bulb is fully submerged, but not
touching the sides or bottom of the glass beaker. The
measurement is complete when the thermometer remains the
same temperature without changing.
1. Put on safety glasses.
2. Place Pyrex measuring cup in the microwave and heat until
you see bubbles breaking the surface of the water. The time it
takes differs for different microwaves.
3. Allow the water to heat unit it comes to a
full boil
. As soon as the water is boiling fully, measure the temperature
with the thermometer and record the measurement to the correct
level of precision. Record the measurement in
Data Table 2
.
4. Allow the water to continue boiling for approximately 5
minutes. After 5 minutes, measure the temperature with the
thermometer and record the measurement to the correct level of
precision. Record the measurement in
Data Table 2
.
5. Once you are done with this experiment, carefully remove the
measuring cup from the microwave using a potholder and set
aside to cool.
6. Turn on the tap water to cold. Let the water run as cold as
possible for approximately 15 seconds.
7. Fill the cup (plastic or drinking) approximately half-full with
cold tap water.

10. 8. Measure the temperature of the cold tap water with the
thermometer and record the measurement to the correct level of
precision. Record the measurement in
Data Table 2
.
9. Add a handful of ice cubes to the cup of cold tap water and
allow them to sit in the cold water for approximately 1 minute.
10. After 1 minute stir the ice water with the thermometer.
11. the temperature of the ice water after 1 minute with the
thermometer and record the measurement to the correct level of
precision. Record the measurement in
Data Table 2
.
12. Allow the ice to remain in the water for an additional 4
minutes.
13. After the additional 4 minutes stir the ice water with the
thermometer.
14. the temperature of the ice water after 4 minutes with the
thermometer and record the measurement to the correct level of
precision. Record the measurement in
Data Table 2
.
15. Convert the temperature measurements for each of the 6
water samples from °F to °C and K. Record the converted
temperatures in
Data Table 2
.

11. III.
Mass Measurements (Conversions)
1. Review the different object(s) listed in
Data Table 3
.
1. Use the masses provided for each of the object(s) in grams
and record in
Data Table 3
.
2. Decide which pennies (before or after 1982) you are using for
your calculations and stick with the choice throughout the
conversions and indicate your choice.
3. Decide if you are using a pen or a pencil and stay with that
choice throughout the entire conversion exercise and indicate
your choice.
*Since we cannot accurately measure mass at home, I have
provided you with the mass of the objects:
Penny after 1982
Penny before 1982
Dime
Quarter

12. Pen
Pencil
2.50 g
3.10 g
2.268 g
5.670 g
16.00 g
4.40 g
Experimental Results
Data Table 1: Length Measurements
Object
Length in cm

13. Length in mm
Length in m
CD/DVD
Spoon
Fork
Key
Data Table 2: Temperature Measurements

14. Temperature in oF
Temperature in oC
Temperature in K
Hot from Tap
Boiling
Boiling for 5 min
Cold from Tap

15. Ice Water – 1
min
Ice Water – 5 min
Data Table 3: Mass Measurements (Conversions)
Mass
Mass in Grams (g)
Mass in Milligrams (mg)
Mass in Kilograms (Kg)

16. Pen or Pencil
3 pennies
1 quarter
2 quarters + 3 dimes
4 dimes + 5 pennies

17. 3 quarters + 1 dime + 5 pennies
key
Key + 1 quarter + 4 pennies
Post-Lab Questions
1. Water boils at 100°C at sea level. If the water in this
experiment did not boil at 100°C, what could be the reason?
2. While heating two different samples of water at sea level, one
boils at 102°C and one boils at 99.2°C. Calculate the percent
error for each sample from the theoretical 100.0°C.
3. In the movie, "
Raiders of the Lost Ark
", Indiana Jones takes a gold idol from a cave. The statue is
resting on a table which is rigged with a weight sensor. The
weight sensor can detect when the weight is removed and will
set off a series of unfortunate accidents. To prevent this from
happening, Indiana replaces the gold idol with a bag of sand.
The volume of the gold idol is approximately 1.0 L. The

18. density of gold is 19.3 g/mL and the density of sand is 2.3
g/mL.
a. Assuming the idol is pure gold, what volume would the bag
of sand have to be in order to weigh exactly the same as the idol
and not set off the booby-traps?
b. Let us assume that Indiana is successful in removing the idol
and returning with it to his laboratory. He decides to determine
if it is pure gold. He weighs the idol and measures the volume
by a water displacement method. The results are mass = 16.5 kg
and volume of water displaced = 954 mL. Is the idol made of
pure gold? Explain your answer based on the experimental
results
4.
An unknown, rectangular substance measures 3.60 cm high,
4.21 cm long, and 1.17 cm wide. If the mass is 21.3 g, what is
this substance’s density (in grams per milliliter)?
5.
A sample of gold (Au) has a mass of 26.15 g. Given that the
theoretical density is 19.30 g/mL, what is the volume of the
gold sample?
6. A student was given an unknown metal. The student
determined that the mass of the metal was 30.2 g. The student
placed the metal in a graduated cylinder filled with 20.0 mL of
water. The metal increased the volume of water to 22.9 mL.
Calculate the density of the metal and determine the identity of
the metal using the table below.
Densities of Metals in g/mL

19. Lead
11.3
Silver
10.5
Nickel
9.90
Zinc
7.14