Name: ______________________________
What do I have to do to feel confident and prepared for the 2014 Pure vs. Mixture and Density Quiz?
Remember when we . .
Students should be able to . . . ANSWERS in BOLD
Properties of Matter
.. created double-bubble
thinking maps to find the
similarities and differences of a
wood and glass sphere.
Describe the concept of physical properties in your own words.
Properties describe matter; you could also call them characteristics or features of matter.
. . . compared the properties of
stretchy plastic material.
If I have 1 cube that is rough, dark brown, and feels light in my hand and a second cube that is smooth,
dark brown and feels heavy in my hand, are they the same type of matter? Include evidence to support
your answer.
The cubes described above are different types of matter because properties define matter; since the
properties are different the matter is likely different.
Give 3 examples of physical properties of a glass marble.
A glass marble has the properties of being smooth, transparent, and without any noticeable odor.
Pure Substances and Mixtures
. . . read in the textbook to find
evidence for which things on the
list were pure substances and
which where mixtures?
..sorted 8 things, like toothpaste
and rice and beans?
Define the concept of a pure substance; be sure to include both types of pure substances.
A pure substance contains only 1 type of matter. It could be a single element or a compound/molecule
as long as the atoms are bonded together.
Name 3 ordinary pure substances
Three examples of ordinary pure substances are copper wire, purified water and sugar.
Describe a mixture. A mixture is a combination of two or more substances that remain individual
substances.
Name 3 ordinary mixtures.
Three examples of ordinary mixtures are cereal in milk, rice and beans, and cola drinks.
When you make a mixture, do any of the ingredients change chemically? How do you know?
The parts of a mixture do not change chemically. Banana slices in fruit salad remain banana. Sugar
added to water still tastes like sugar.
What defines a homogenous mixture? Give an example.
A homogenous mixture is a mixture that has ingredients spread evenly throughout. Sugar water is an
example of a homogenous mixture because it tastes the same throughout.
What defines a heterogeneous mixture? Give an example.
A heterogeneous mixture is a mixture that has ingredients that ARE NOT spread evenly throughout.
You would see more of one ingredient in some parts. Chicken noodle soup is an example of
heterogeneous mixture because you will have different amount of broth, noodles and chicken in each
spoonful.
Draw the atoms/molecules of a homogenous and heterogeneous mixture using open and filled
circles.
Heterogeneous Mixture
Spread unevenly
Homogenous Mixture
Spread evenly throughout
Density
. . .put different items in order
from lowest density to highest
density and then measured
their density.
Define the concept of density in your own words.
Density describes the amount of mass for an object’s size. Low density matter has a low amount of
mass for its size.
Describe the difference between mass and volume.
Mass is a measure of the amount of matter (atomic stuff, atoms/molecules). Volume is a measure of
the amount of space occupied by an object.
Describe the size of units you use to measure and report mass and volume.
Mass is most often reported in grams, but you can use kilograms. Volume can be reported in cubic
centimeters (cm3) or in milliliters (ml). 1 cm3 = 1 ml. Larger volumes are measured in liters, like 2-liter
soda bottles.
What is the density of a wood block that has a mass of 40 grams and a volume of 80 cm3.
Density = mass/ volume, so the density of the wood = 40 g/ 80 cm 3 = 0.5 g/ cm3
..measured the density of
samples of different sizes.
What units of measure do you have when you calculate density? The units of measure for something I
calculate are the units of measure for whatever quantities I use to make the calculation. Since density
is mass divided by volume, the unit for density are g/ cm3
Draw the density triangle and the density heart.
Density =
ass
olume
m
D*v
Use the density triangle to write the formula would you use to find mass if you know the density and the
volume of an object mass.
mass = Density * volume
Use the density triangle to write the formula would you use to find volume given the density and the
mass of an object.
volume = mass/Density
Describe if changing the size of a sample of a substance changes its density.
No changing the size of the sample won’t change the density because the amount of mass in a set
volume is constant. Said another way, changing the size of the sample won’t change the density
because when you change the size, the mass also changes.
. . . used colored circles and
drew on our desks to show
different densities.
Describe the features of a particular type of matter that can explain why it has a high density or a low
density.
The density of matter is affected by how tightly packed the atoms/molecules are and by the type of
atoms/ molecules (elements) that make up the matter.
Would a substance with a high density have a high amount or a small amount of matter packed in a
specific volume?
A substance with a high density would contain a high amount of matter packed in a specific volume.
Which substance is more dense based on these drawings?
Support your answer with evidence.
Substance B is more dense because
there is more matter packed in the same space
A
B