Chapter 5 section 5.1
Define: particle theory of matter
scientific method
heterogeneous
Homogeneous
solution
mechanical mixture
physical change
chemical change
physical property
density
volume
chemical property
combustibility
mass
precipitate
Chemistry- The science that deals with matter (properties, composition, structure,
interactions) and the energy involved in these interactions.
Matter- anything that takes up space and has a mass. Made up of particles called atoms.
Exploring Matter P. 156-157
Questions:
1.
List three different areas that our knowledge of science includes.
2.
In science, what is the difference between the terms “model”, “law” and
“theory”?
3.
State one common example for each of the following: a science model, a law
and a theory.
4.
Copy the 5 points in the particle theory of matter.
5.
Use the particle theory to explain how water evaporates from your hands after
washing. (Hint: Aside from sanitary reasons, why do many washrooms have an
electric hot air hand drier?
6.
A) From P. 157, explain the difference between a pure substance and a mixture.
B) What is the difference between a solution and a mixture?
Physical and Chemical Change: Pages159 , 164 and 169
Questions:
1.
Give three examples of a physical change.
2.
Give three examples of a chemical change.
3.
What is a precipitate?
4.
Identify clues or words that would represent a physical change.
5.
From the discussions in class and the information in your text, list
characteristics that identify a chemical change.
Chemical and physical properties:
All substances have properties that we can use to identify them. For example we can
identify a person by their face, their voice, height, finger prints, DNA etc.. The more of
these properties that we can identify, the better we know the person. In a similar way
matter has properties - and there are many of them. There are two basic types of
properties that we can associate with matter. These properties are called Physical
properties and Chemical properties:
Properties that do not change the
Physical
chemical nature of matter
properties:
Properties that do change the
Chemical
chemical nature of matter
properties:
Examples of physical properties are: color, smell, freezing point, boiling point, melting
point, infra-red spectrum, attraction (paramagnetic) or repulsion (diamagnetic) to
magnets, opacity, viscosity and density. There are many more examples. Note that
measuring each of these properties will not alter the basic nature of the substance.
Examples of chemical properties are: heat of combustion, reactivity with water, PH,
and electromotive force.
The more properties we can identify for a substance, the better we know the nature of that
substance. These properties can then help us model the substance and thus understand
how this substance will behave under various conditions.
Physical Properties, General
(Boiling Point, Freezing Point, Melting Point, Density, Refractive Index, Specific
Gravity)
Physical changes are those changes that do not result in the production of a new
substance. If you melt a block of ice, you still have H2O at the end of the change. If you
break a bottle, you still have glass. Painting a piece of wood will not make it stop being
wood. Some common examples of physical changes are; melting, freezing, condensing,
breaking, crushing, cutting, and bending. Special types of physical changes where any
object changes state, such as when water freezes or evaporates, are sometimes called
change of state operations.
Chemical changes, or chemical reactions, are changes that result in the production of
another substance. When you burn a log in a fireplace, you are carrying out a chemical
reaction that releases carbon. When you light your Bunsen burner in lab, you are
carrying out a chemical reaction that produces water and carbon dioxide. Common
examples of chemical changes that you may be somewhat familiar with are; digestion,
respiration, photosynthesis, burning, and decomposition
Density P. 165-166- Take a look at the two boxes below. Each box has the same
volume (is of the same size). If each ball has the same mass, which box would weigh
more? Why?
BOX A
BOX B
The box that has more balls has more mass per unit of volume. (It has more material in itmore atoms.) This property of matter is called density. Thus density is defined as the
mass per unit volume.
The density of a material helps to distinguish it from other materials. Since mass is
usually expressed in grams and volume in cubic centimeters, density is expressed in
grams/cubic centimeter. (g/cm3)
Mass= Volume x Density
Density= Mass/Volume
Volume= Mass/Density
Section 5.2
Define: solution
solvent
solute
Colloid
Tyndall effect
Pages 170 to 174
Do questions 1 to 4: Check Your Understanding page174
alloy
suspension
Section 5.2- Mixtures
Solutions All solutions:
- are mixtures of solute and solvent
- are homogeneous due to their extremely small particles
Solutions are usually transparent and this distinguishes them from mechanical
mixtures. Exceptions: alloys. Alloys are homogeneous mixtures of more then one
metal. Alloys are important because adding small amounts of other substances
greatly alters the properties of a pure metal
Examples: 1. Wood’s Metal- a mixture of bismuth, lead, tin and cadmium
2. steel- a mixture of iron and carbon
3. Stainless steel- a mixture of iron, carbon, nickel and chromium.
4. coins- a nickel is 75% copper and 25% nickel
5. Jewelry- yellow gold is a combination of gold and copper.
Mechanical Mixtures:
Suspensions- technology can speed up the separation of a suspension
Ex- filtering muddy water
- technology can also prevent a suspensions fro separating
Ex- emulsifying agents
Homogenization of cow’s milk
Colloid- the dividing line between solutions and mechanical mixtures, because they
appear homogeneous due to their extremely small particles.
- How do you distinguish between a colloid and a solution?
A beam of light!! The light will not be scattered by the particles in a
solution, while it will b scattered by particles in a colloid. This is known
as the Tyndall Effect.
Section 5.3
Define: compound
element
alchemist
electrolysis
Pages 175 to 182: Compounds and Elements
Read pages 175 to 182 and answer the following questions.
1. List three examples of a compound.
2. List three examples of elements.
3. In your own words, explain the law of conservation of mass.
4. In your own words, explain the law of definite proportion.
5. Copy updated chart on page 175
Section 5.4
define: atom
element
Dalton’s atomic theory
Atomic Theory: Explaining Chemical Facts and Laws – Pages 182 to 186
Questions:
1. What is an atom?
2. Who is John Dalton and what did he accomplish?
3. List the points of Dalton’s Atomic Theory.
4. Why is Dalton’s atomic theory so important?
5. What is the difference between a Law and a Theory?
6. Describe the similarities and differences between the particle theory and
Dalton’s atomic theory.