Density
Intro Chapter
Density Demo #1
Density Demo #1
• Problems:
– What will happen when the small steel ball
is placed in the water?
– What will happen when the large steel ball
is placed in the water?
• Hypotheses:
– The small steel ball will _________ when
placed in water.
– The large steel ball will _________ when
placed in the water.
Density Demo #1
Density Demo #2
• What will happen when an egg is
placed in beaker 1?
• What will happen when an egg is
placed in beaker 2?
Density Demo #2
• Observe the eggs when each is placed
in beaker 1 and beaker 2.
• What happened? Why?
Breaking Down Density
• What do all objects
have?
– ___________________
• Remember, all objects are
made up of something called
_________________
– Because objects have
mass and are made up of
matter they also
have_________________.
– All objects take up space
Density Example
1. Students in a Classroom
•
Think about the number of students in
this room. If you had 10 students
(represent molecules) in the room, how
would that compare to having 250
students (molecules) in the room?
Which situation would be denser?
Density
• Write a definition for density. Think
about the examples provided.
– The amount of matter in a given volume.
– It’s a ratio.
Density
• Write an equation for Density.
– Remember it’s a ratio.
Example Problems
• Directions: Find the missing values
for the following density problems.
1. Write the correct equation to use.
2. Plug in the numbers.
3. Circle your final answer. (don’t forget
units)
Density
• Example Math Problem:
– A student determines the mass of a metal
paperclip to be 1.42g (grams).
– The student also determines the volume
and finds that it has a volume of 2mL.
• Determine the density of the paperclip.
Example Problems
2. Mass = 150g
Volume = 30cm3
Density = ?
3. Volume = 70 cm3
Density = 30g/ cm3
Mass = ?
Density of Water / Salt Water
1. Using the appropriate tools,
determine the density of water / salt
water.
2. Create a table to display your results.
3. Using the data you found,
approximate the density of the egg.
Density Data Table
• Show your work!
Density
Saltwater
Freshwater
Mass
Volume
Density of Water / Salt Water
4. If an object is denser than water, what
will happen to it when it is placed in
water?
5. If an object is less dense than water,
what will happen to it when it is
placed in water?
Density of Water / Salt Water
6. If you were to carefully pour the water
into salt water trying to keep them
from mixing. What should happen?
Salt Water Ice Lab & Density
• Do your calculated results make sense with
what you observed in the ice lab?
Salt Water Ice Lab & Density
• Do your calculated results make sense with
what you observed in the ice lab?
H20
H20
H20
H20
H20
H20
H20
H20
NaCl
H20
NaCl
H20
NaCl
H20
NaCl
H20
NaCl
H20
NaCl
H20
NaCl
H20
H20
Example Word Problem
• During the ice lab, Mrs. Gregory obtained a
10mL sample of the salt water from the beaker
and massed it on the electronic balance. She
determined the mass to be 9.9g. She then took
a 10mL sample of melted blue ice water and
massed it on the balance. She figured out that
the mass was 9.6g. Calculate the density of
both substances and determine which is denser,
the salt water or blue ice water. Do your
calculated results make sense with what you
observed in the ice lab?