Transcript Introduction to Matter

Introduction to Matter
Table of Contents
Describing Matter
Measuring Matter
Changes in Matter
Energy and Matter
Introduction to Matter - Describing Matter
Modeling an Atom
Pencil “lead” is made of mostly
graphite, a form of carbon. Two ways
to model atoms used in this
presentation are shown here for
carbon.
Introduction to Matter
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Introduction to Matter
Introduction to Chemistry
HindenburgHydrogen Gas
Explosion
Safety Protocol:
1. Do NOT touch anything on the back table until instructed to
do so.
2. Follow Lab Directions (if you are unsure, then ask).
3. Notify teacher of spills, broken or breaking glassware, and any
other problems.
Introduction to Matter
Identifying Substances in
an Unknown Mixture
Goal: [Use the title to create your goal]
Background/Procedure: You have an unknown mixture (Un) that contains 2
pure substances (compounds). You must identify both of these substances.
You will have 4 known compounds to use to find out which 2 of these 4
substances are in the unknown mixture: citric acid (CA), calcium
carbonate (CaCO3), sodium chloride (NaCl), and baking soda (BS). You
will be given a well plate and a small amount of water (use 3 drops for the
tests). THE WELLS SHOULD NOT BE MORE THAN HALF-FULL W/ SOLID!
Hypothesis: Predict which two compounds you think are in the unknown
AFTER YOU PERFORM THE UNKNOWN TEST. This should also be based
on your initial observations of the unknown and the other solids.
Results: Create a 2 column table with one side for the substance PAIRS
(including the unknown) and the other for your observations.
Conclusion: State which 2 substances are in the unknown and explain why
this is true BASED UPON YOUR EVIDENCE (the results).
Introduction to Matter
Learning Objectives
Chemistry studies matter and how it changes. The 3 types of
matter are Elements, Compounds, and Mixtures.
1. Define elements and be able to identify examples of
elements.
2. Explain the relationship between elements and compounds (&
be able to give examples of each).
3. Describe the properties of a mixture.
•
•
Heterogeneous vs. Homogeneous
Separating a simple mixture
Introduction to Matter
Elements, Compounds, & Mixtures
Goal: Determine which dish represents the particles of an
element, which one represents the particles of a compound, and
which one represents the parts of a mixture.
Background: Nut =
Bolt =
Washer =
*Create a table to summarize your results/hypothesis.*
Conclusion: Explain why you chose each dish to represent either
an element, compound, or mixture.
Put the following in your lab notebook as well…
Extension Activity: List all of the elements found in the foods you
are examining by using the wrappers. [Periodic Table on p. 182]
Introduction to Matter
Elements
Element- a pure substance that CANNOT be broken
down into any other substance (Examples: gold- Au,
calcium- Ca, aluminum- Al, carbon- C, oxygen- O2,
hydrogen- H2)
What’s the easiest way to tell if a substance is an
element?
If it’s on the periodic table & it can’t be broken down
because it is made of ONE pure element.
Introduction to Matter
Element Review (in your lab notebook)
Label each substance as an element or a compound. Then determine which
elements are present and how many parts are present by examining the
number after the element symbol. No number = 1. ONE capital letter or ONE
capital and ONE lowercase letter indicate a certain element.
1. He
2. O2
3. CO
4. H2O
5. Mg
6. CH4
7. C
8. N2
9. Co
10.Mg(C2H3O2)2
Introduction to Matter
Learning Objective
2. Explain the relationship between elements and
compounds (& be able to identify examples of each).
Introduction to Matter
Demonstration of Compound Formation
Big Questions: Do the elements have similar properties to the
compounds they make up? How does this relate to the food we eat?
Demo: Making sodium chloride (NaCl), the main ingredient in table salt,
from sodium metal (Na) and chlorine gas (Cl2).
Properties of…
Sodium- highly reactive (esp. to water)
Chlorine gas- toxic if inhaled, highly reactive
Sodium chloride- low reactivity (well, we eat it)
Conclusion: Do elements share the same properties as the compounds
they make up? How do you know?
NO, sodium is a reactive metal and chlorine is a toxic gas that’s
reactive. Sodium chloride is a compound we eat that has low reactivity.
Introduction to Matter
Properties: Compounds & Their Elements
Compound/ Elements in the
Properties Compound
CaCl2
White
Solid, Ice
Melt Salt
MgO
White
Solid,
Drying
Agent
KCl
White
Solid, Salt
Substitute
Ca = Calcium
Cl = Chlorine
Physical Properties
of the Elements
Calcium- Dark, dull Calcium- reacts to
gray metal
water
Chlorine- yellowish- Chlorine- Toxic gas
green gas
Mg = Magnesium Magnesium- Shiny
gray metal
O = Oxygen
Oxygen- colorless
gas
K = Potassium
Cl = Chlorine
Chemical Properties
of the Elements
Magnesium- reacts
to hot water
Oxygen- reacts to
iron & other
substances
Potassium- dull
Potassium- highly
gray metal
reactive to water
Chlorine- yellowish- Chlorine- Toxic gas
green gas
Introduction to Matter
Compounds
Compounds- a pure substance consisting of 2 or more different
elements that are chemically bonded. (Examples: water or H2O, carbon
dioxide or CO2, “table salt” or sodium chloride- NaCl)
Elements
NH3
Compounds
NH3
What’s the easiest way to tell if a substance is a compound?
If it CANNOT be broken down by physical means (dissolving, magnetism,
etc.) but can be broken down with a chemical reaction (breaking down iron
chloride to produce chlorine gas), & if it is made up of 2 or more elements
bonded together.
Introduction to Matter
Compound Review: Think-Pair-Share
1. For carbon monoxide (CO), is it a compound, element, or mixture? How
do you know?
Compound- 2 or more different elements bonded together.
2. If it is a compound, then how do the properties of the compound itself
compare to the elements that make up carbon monoxide?
The properties of the elements are different from the compound.
(Carbon is a black solid used in pencil “lead” and Oxygen is a gas we
breath in, while Carbon Monoxide is a toxic gas and a pollutant)
3. Can a compound be broken down by physical means (picking out the
parts, filtering, etc.)? Can a compound be broken down by chemical
means (with a chemical reaction)?
A compound cannot be broken down by physical means, but can be broken
down by chemical means.
Introduction to Matter
Learning Objective
3. Describe the properties of a mixture.
•
•
Heterogeneous vs. Homogeneous
Separating a simple mixture
Introduction to Matter
CSI BAMS: Ink Analysis
Jan. 13, 2015
Introduction to Matter
Crime Scene: Main Office
Tuesday 1/13/15 8:01 A.M.
Introduction to Matter
Details of the Crime
The office was left in a mess with papers and folders everywhere, and the
secretaries are currently missing.
A ransom note was left at the main office stating that “Enough is enough.
If you have ever want to see your precious secretaries again, then place
10 million dollars in an unmarked blue bag next to the dumpster out
behind the school (the one where students don’t hang out). No cops, no
friends, no one at all! If you involve the authorities, then you’ll never see
your secretaries again!”
Three suspects have been found.
The ink from the note has been transferred to you for your analysis of the
evidence.
You must provide a labeled sketch of the ink analysis and your
reasons for who you believe committed the crime.
Introduction to Matter
Suspect #1: Mr. Johnson
Mr. Johnson seemed to be restless as of late with
constant complaints of not being recognized as an
actual teacher. He was very disappointed with the
office laughing at his idea for a Lord of the Rings
club. He had his Justin Bieber fan club membership
revoked as well.
Introduction to Matter
Suspect #2: Mr. Snyder
Mr. Snyder has been frustrated since the secretaries
have been teasing him about his thick moustache. He
refuses to trim it or shave it off. Also, he believes that it
gives him super powers. Rumor has it that if he did
shave it off, then he would be no smarter than a 5th
grader. However, this rumor was likely started by Mr.
Snyder himself.
Introduction to Matter
Suspect #3: Mr. McManus
He has recently showed his frustration because he did not
make it to the next round for American Idol. He was also
kicked out of the Miley Cyrus fan club, which crushed him
like a wrecking ball. He believes the secretaries got him
kicked out of the fan club and posted an online video of
his atrocious “YMCA” rendition from American Idol. It has
since been removed for supposed copyright purposes.
Introduction to Matter
As Crime Scene Investigators…
•Your task is to analyze the ink pens of the crime scene and
the ones recovered from the homes of the suspects.
•You will compare, by chromatography, the component parts
of the ink.
•With this information, you will be able to determine who
wrote the ransom note and kidnapped the secretaries.
Introduction to Matter
Separating the Ink Mixture
1.
GENTLY press the tip of each suspect’s pen once or twice onto the
paper because the smaller amount of ink, the less time it takes to
visibly separate the parts of the ink mixture. Follow the order
indicated in the diagram on the left side of the SMART Board.
2.
Set up the chromatography paper on the inside of the rim of the glass
so it stands straight up and will NOT fall or bend.
3.
Do NOT let the bottom of the paper touch the side of the beaker nor let
the ink dot be submerged in the liquid. This could cause an error in
your results due to an incomplete separation.
4.
Allow your setup to sit for 30 minutes and then let it dry for a few more
minutes.
5.
Examine and sketch your results in your lab notebook. This sketch
should be labeled with whose pen it was and the colors that separated
out.
Introduction to Matter
What Is Ink?
Several organic dyes - blue, red, black, etc. (This
can form an ink "fingerprint.")
Tags that signify the manufacturing year - isotopes
Introduction to Matter
Why is ink important forensically?
Fraud cases
Embezzlement
Theft
Kidnapping and
Ransom
Threats
Documentation
Introduction to Matter
How is ink used as a forensic tool?
• A small sample is dissolved.
• This sample is compared to a known sample.
• Each pen manufacturer has its own "recipe" for ink, so a
sample from a document can lead to the discovery of
the type of pen used.
• The tags in ink can determine the year the pen was
manufactured.
Introduction to Matter
What is chromatography?
• Qualitative analysis.
• Separates mixtures into individual parts.
Introduction to Matter
Learning Objective
3. Describe the properties of a mixture.
•
•
Heterogeneous vs. Homogeneous
Separating a simple mixture
Introduction to Matter
Food as a Mixture (No lab write-up)
Goal: Using a magnet, attempt to separate one part of Total
cereal.
Procedure: Roll the magnet around on the bottom of the
plate continuously for several minutes, and observe.
Conclusion: What did you extract?
Introduction to Matter
Types of Mixtures (No lab write-up)
Look up the definitions of homogeneous and
heterogeneous mixtures in your textbook (p. 13).
Create one of each type of mixture (Homogeneous- in the
large plastic cup, Heterogeneous- in the small paper cup
w/o salt) and explain them to the Professor.
Explain how you can separate the parts of each type of
mixture.
Heterogeneous- pick out the parts somehow
Homogeneous- boil off the water, let it evaporate
Are the parts of a mixture chemically bonded together?
NO
Introduction to Matter
Mixtures
Mixtures- combination of 2 or more pure substances (NOT in a
set ratio) that retain their individual properties, so they can
separated by physical means. (Examples: salt water, a
homogeneous mixture; and trail mix, a heterogeneous mixture)
How can you tell if you have a mixture?
If you can separate its parts by physical means (magnetism,
dissolving, boiling, etc.) & if it’s parts are not chemically bonded
together.
Introduction to Matter
Correctly identify what each diagram represents.
A.
B.
C.
D.
1- compound, 2- compound, 3- mixture
1- element, 2- compound, 3- mixture
1- mixture, 2- compound, 3- element
1-element, 2- mixture, 3- compound
1
2
3
Introduction to Matter
A pure substance that cannot be broken down is
called a(n)
A.
B.
C.
D.
mixture
compound
element
Mr. Nye
Introduction to Matter
Determine the number of parts for each element in
the compound Calcium Sulfate (CaSO4).
A.
B.
C.
D.
0 calcium, 0 sulfur, 4 oxygen
1 calcium, 4 sulfur, 4 oxygen
1 Calcium, 1 sulfur, 4 oxygen
4 calcium, 4 sulfur, 4 oxygen
Introduction to Matter
How is a compound different from an element?
A. Compounds are made of up of 2 or more different
elements that are chemically bonded.
B. Compounds are 2 or more elements that are NOT
chemically bonded.
C. Compounds are made up of 2 or more different mixtures.
D. Compounds are sentences that have “and, but, or, nor,
yet, and sometimes so” in them.
Introduction to Matter
How is a compound different from a mixture?
A. They’re the same thing.
B. Mixtures CANNOT be separated by physical means b/c
they are made up of 2 or more elements bonded together
while the parts of a compound are not bonded together.
C. Chemistry is too hard already!
D. Compounds CANNOT be separated by physical means
b/c they are made up of 2 or more elements bonded
together while the parts of a mixture are not bonded
together.
Introduction to Matter
Correctly identify the following substances as an
element, compound, or mixture: ocean water,
hydrogen gas (H2), carbon dioxide gas (CO2).
A. Ocean water- compound, hydrogen gas- element,
carbon dioxide gas- mixture.
B. Ocean water- mixture, hydrogen and carbon dioxide
gas are both compounds.
C. All of them are compounds.
D. Ocean water- mixture, hydrogen gas- element, carbon
dioxide gas- compound.
Introduction to Matter
How could you separate out the iron in a mixture of
iron filings, salt, and sand? How could you
separate out the salt in this mixture?
A. Iron filings- use your magnetic personality, salt- rub
some food on it
B. Iron filings- use a magnet, salt- pick the crystals out
C. Iron filings- dissolve in water, salt- dissolve in water then
filter
D. Iron filings- use a magnet, salt- dissolve it in water then
filter
Introduction to Matter - Describing Matter
Ratios
A ratio compares two numbers. It tells you how much you
have of one item compared to how much you have of
another. For example, a cookie recipe calls for 2 cups of flour
to every 1 cup of sugar. You can write the ratio of flour to
sugar as 2 to 1, or 2:1.
The chemical formula for rust, a compound made from the
elements iron (Fe) and oxygen (O), may be written as Fe2O3.
In this compound, the ratio of iron atoms to oxygen atoms is
2:3. This compound is different from FeO, a compound in
which the ratio of iron atoms to oxygen atoms is 1:1.
Introduction to Matter - Describing Matter
Ratios
Practice Problem
What is the ratio of nitrogen atoms (N) to oxygen atoms
(O) in a compound with the formula N2O5? Is it the same
as the compound NO2? Explain.
N2O5 contains two nitrogen atoms for every five oxygen
atoms. Both N2O5 and NO2 are made up of only nitrogen
atoms and oxygen atoms. However, the two compounds
are different because NO2 contains one nitrogen atom
for every two oxygen atoms.
Introduction to Matter - Describing Matter
Building Vocabulary
A definition states the meaning of a word or phrase by telling
its most important feature or function. After you read the
section, use what you have learned to write a definition of
each Key Term in your own words.
Key Terms:
matter property
chemical
molecule
mixture
chemistry
element
compound
substance
heterogeneous
mixture
chemical formula
atom
homogeneous
mixture
physical property
chemical
solution bond
Examples:
Matter
A
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chemical
mixture
manyiscases,
anything
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made
atoms
that
of two
is
combine
has
a or
characteristic
mass
more
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takes
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pure
particles
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substance
called
elements,
molecules—groups
compounds,
that describes
or its
both—that
ofability
two or
tomore
are
change
together
atoms
into held
in
Chemistry is the study of the properties of matter and
different
together
the
samesubstances.
by
place
chemical
but are
bonds.
not chemically combined.
how matter changes.
An
element is a apure
that
cannot
be or
broken
A
puresubstance
substance
made
In compound
chemistry, aissubstance
is a single
kindofoftwo
matter
down
into any other
substances
by chemical
or
In
a is
heterogeneous
mixture,
you
see
more
elements
chemically
combined
a setthe
ratio.
that
pure, meaning
it always
has can
a in
specific
physical parts.
means.
different
makeup—or
a specific
set of
A compound composition—and
may be represented
by a chemical
An
atom
is
the basic
particle
from which
allcompound
elements
properties.
The
substances
in a homogeneous
mixture
are so
formula,
which
shows
the elements
in
the
are
made.
evenly
that
youiscan’t
see the different
parts.
and
themixed
ratioproperty
of
atoms.
A physical
a characteristic
of a pure
When
atoms
they
a chemical
bond,
substance
that
be observed
without
changing
it
A
solution
is combine,
ancan
example
of form
a homogeneous
mixture.
which
is
a
force
of
attraction
between
two
atoms.
into another substance.
Introduction to Matter - Describing Matter
Links on Describing Matter
Click the SciLinks button for links on describing matter.
Introduction to Matter
End of Section:
Describing
Matter
Introduction to Matter
Learning Objectives
1. Describe how the density of a material is determined.
Introduction to Matter
Density Demonstrations
D = M/V (The amount of mass in a certain amount of space)
What is the density of water (in g/mL)?
1.0 g/mL
Soda Cans- Constant volume, but different masses
How does mass affect density (if the volume is the same)?
Heavier mass = Greater Density
Metal Spheres- Constant mass, but different volumes
How does volume affect density (if the mass is the same)?
Greater volume = Lower Density
Pumice (Big Ol’ Rock)- Why does it float?
Large volume and Low Mass (makes it less dense than water)
Introduction to Matter
Noggin Knockers (12 pts.- from p. 15: 2b, 3a, 3b, 3c)
1 (6 points- 2 points per CORRECT element and number)C = carbon (6 parts); H = hydrogen (12 parts); O = oxygen (6
parts)
2 (2 points)- Heterogeneous- you can see the parts (not evenly
mixed), Homogeneous (AKA a solution)- can’t see the parts OR
b/c they are evenly mixed.
3 (2 points)- Seawater contains 2 compounds (water and salt) and
they are not bonded together OR the properties of salt and water
do NOT change.
4 (2 points)- Let the water evaporate OR boil off the water so that
only baking soda remains after the water evaporates or boils off.
Introduction to Matter
Making Sense of Density Lab
Problems (in place of the goal): Does the density of an
object change if the same object is broken into pieces? Can
density be used to identify a substance?
Hypothesis: Make your hypothesis answering the questions
above (in complete sentences).
Procedure
1. Examine the data table on the next slide for the
measurements you will need to make. You will be
determining the density of 1 type of object of 4 different
sizes.
2.
Use the lab equipment provided to carry out these
necessary measurements. Remember to zero the balance
when needed.
3.
Complete the Analyze & Conclude questions after the data
table is completed.
Introduction to Matter
Density of Colored Cylinders Table (Sample)
Color & Size of
Object
(Example below)
Mass
(g)
Initial
Volume
(mL)
Vi
Red Cylinder
(largest)
Red Cylinder
(2nd largest)
Red Cylinder
(3rd largest)
Red Cylinder
(smallest)
Purple Cylinder
(largest)
Purple Cylinder
(2nd largest)
Include other
2 sizes of 2nd object
too.
Final Volume
(mL)
Vf
Volume
Change
(mL)
Vf – Vi
Density
(g/mL)
D = M/V
Introduction to Matter
Analyze & Conclude
1. For each object you tested, compare the
density of the largest cylinder with the
densities of the smaller ones. Were they
mostly similar or quite different? Keep in the
mind that the smallest cylinder’s measured
density is probably slightly inaccurate.
Substance
Density (g/mL)
Maple Wood
0.77
Polypropylene
0.90
Polystyrene
1.03
Nylon
2. Use your results to explain how density
Acrylic
can be used to identify a substance. Guiding
Questions: If you have 2 samples of the same
Polyurethane
substance and one sample is much larger (in
mass and volume), will the actual density be
Phenolic
different (examine your results if needed)?
Polyvinylchloride
Why or why not?
(PVC)
1.15
3. What are the colors & identities of your
two substances?
PTFE (Teflon)
2.2
Aluminum
2.71
1.17
1.23
1.32
1.37
Introduction to Matter
Using Density to Identify a Substance
Background- In 1982, the metal used in pennies changed.
Goal- Use density to identify the metals used in pre-1982 and post-1982
pennies.
Procedure
1. Determine your own procedure based upon your experiences with
previous density experiments. Hint: Use as many of the pennies as
you can (15+) and figure out the density of the stack of pennies. Do NOT
use 1982 pennies!
2. Make an appropriate data table for this experiment and include
appropriate headings for the columns and rows. Hint: Use pre-1982
(before 1982) and post-1982 (after 1982) for the rows.
Introduction to Matter
Analyze & Conclude
Examine the densities in the
table on the right to determine
the composition of the pre1982 and post-1982 pennies.
1. Write what pre-1982 and post1982 pennies are mostly made
of for your conclusion and
EXPLAIN how you know by
providing evidence (data)
from the experiment.
Metal
Density
(g/mL)
Copper
8.9
Aluminum
2.7
Platinum
21.5
Iron
7.9
Zinc
7.1
Introduction to Matter
Noggin Knockers (8 pts.- Quiz)
1a (2 points- 1 point for the correct value and 1 point for the correct
units)12 g/4 mL = 3 g/mL
1b (1 point)- Aluminum
2 (1 point each)- (a) Element, (b) Heterogeneous mixture, (c)
Compound, (d) Homogeneous mixture
3 (1 point)- Properties are different.
Introduction to Matter
Learning Objectives
2. Identify the units used the amount of space occupied by
matter (volume).
3. Determine the difference between weight and mass.
Introduction to Matter
Weight vs. Mass
Weight is the measure of the force of
gravity on your body.
For example, the moon has about 1/6
the gravity of Earth. So, if you weigh
180 pounds on Earth, then you would
only weigh 30 pounds on the Moon.
Mass is the amount of matter in an
object. So, if your mass is 100 kg then
you would still have a mass of 100 kg on
the moon.
Determine your mass and weight on
Earth and the Moon.
Mass = Weight / 2.2
Introduction to Matter
Volume & Density
Volume is the amount of space occupied by
matter and is usually measured in Liters (L),
milliliters (mL), and centimeters cubed (cm3)
which is equal to a milliliter.
1 mL = 1 cm3
Volume can be determined several ways:
1. Multiplying the length, width, and thickness for
regular shaped objects such as a brick or cube.
2. Submerging the object in water and calculating
the CHANGE in volume for irregular shaped
objects such as a rock or piece of gold.
Introduction to Matter
Suppose you have an unknown solid substance and
you want to know if it’s gold. How could you
determine if the substance is real gold?
A.
B.
C.
D.
Determine its mass.
Give it to the Professor to examine.
Determine its weight.
Determine its density.
Introduction to Matter
Why do ice cubes and wooden boats float in water?
A.
B.
C.
D.
E.
Wood floats in water, but ice does not.
Wood and ice have a density greater than 1.0 g/mL.
Ice is lighter than water.
Ice and wood both have a density less than 1.0 g/mL.
Only ice floats in water, wood is too heavy to float.
Introduction to Matter
You perform an experiment with very little error to
determine an unknown object’s density. You find
the object’s mass to be 21 g and its volume to be 3
mL, then what is the identity of the object? Use the
table below.
A. Zinc
B. Iron
C. Aluminum
D. Copper
Metal
Density
(g/mL)
Copper
8.9
Aluminum
2.7
Platinum
21.5
Iron
7.9
Zinc
7.1
Introduction to Matter
If a ball that has a density of 1.73 g/cm3 is placed in
the beaker, where will the ball come to rest?
A.
B.
C.
D.
On top of liquid A
Between liquids B and C
Between liquids C and D
On the bottom of the beaker
Introduction to Matter
The amount of matter in an object is its
A.
B.
C.
D.
mass
volume
density
temperature
Introduction to Matter
Suppose in your lifetime, the technology came out
where you could go to various planets. What would
happen to your weight and mass as you go from
planet to planet?
A.
B.
C.
D.
What planet am I on now???
Weight- stay the same; Mass- stay the same
Weight- change; Mass- remain the same
Weight- change; Mass- change too
Introduction to Matter
What property of the rock is being measured in the
picture below?
A.
B.
C.
D.
Temperature
Density
Volume
Mass
Introduction to Matter
Density of a Human Being
Mass (in kg) = Weight / 2.2
Convert Mass to grams =
kg =
g
Volume = Amount of water displaced (by overflowing water)
– Determine your group’s total volume
– Add up the total volumes from each group (which
equals the volume of the submerged person)
Density = Mass/Sum of Total Volumes
Introduction to Matter
End of Section:
Measuring Matter
Introduction to Matter
Noggin Knockers (8 points- from p. 20: 1b, 2a, 3b, 4)
1 (2 points)- Weight changes depending on the force of
gravity from place to place while mass remains the same.
2 (1 point)- Volume is measured in cubic centimeters
3 (2 points)- If a substance is more dense than water, it will
sink; if it’s less dense than water, the object will float.
4 (3 points)- 277 g/38 cm3 = 7.3 g/cm3 (Tin)
Introduction to Matter
Learning Objectives
1. Describe what a physical change is (and give examples).
2. Describe what a chemical change is (and give
examples).
3. Identify at least 3 sources of evidence that a chemical
reaction has taken place.
Introduction to Matter
Chemical vs. Physical Changes Lab
Goal- Identify the following
changes as a chemical or
physical change.
Change
Post-lab Questions
Crumpling paper (don’t do)
1. Is chromatography a chemical
Lighting a match (don’t do)
or physical change?
2. Identify the following as a
chemical or physical
property:
a) water (as ice) melts at 0oC
b) water’s density = 1.0 g/mL
c) gasoline can burn
d) iron can rust.
e) *Can these properties be
used to help identify a
substance?
Dissolving sugar (don’t do)
Crushing chalk (1 pc.) w/ lid
2 droperfuls of Vinegar +
Crushed chalk in test tube
Boiling Water (don’t do)
1 droperful of Calcium
chloride + 1 droperful of
sodium carbonate in test tube
3. What are at least 3 signs of a
chemical change?
Bending a light stick (demo)
Observations
Paper crinkled
Light and heat
were given off
Chemical
or Physical
Change
Introduction to Matter - Changes in Matter
Changes in Matter
If a substance undergoes a physical change, then that
substance is still the same substance after that change. A
change in matter that produces one or more new
substances is a chemical change, or a chemical reaction.
Introduction to Matter
Electrolysis of Copper Chloride (No lab write-up)
Goal- Determine what happens to a solution of copper
chloride when electricity is passed through it.
Pre-lab: Is copper chloride (CuCl2) an element, compound,
or mixture?
During Lab: What did you observe?
Post-lab: What did you observe forming on the paper clips?
What substance formed on the paper clips?
Conclusions: Is the electrolysis of copper chloride a
chemical or physical change? How do you know (from the
experiment)? So, can compounds be separated into their
elements by chemical means?
Introduction to Matter
Examples of Chemical Change
Introduction to Matter
Which of the following is NOT a likely sign that a
chemical change took place?
A.
B.
C.
D.
The substance changed in color.
Light and heat were produced.
Bubbles of gas were formed.
A liquid was cooled and changed into a solid.
Introduction to Matter
What’s the primary difference between a chemical
and a physical change?
A. In a physical change, the substance is still the same substance
after the change.
B. In a chemical change, the substance is still the same substance
after the change.
C. In a physical change, one or more new substances are formed.
D. In a chemical change, water burns.
Introduction to Matter
Which of the following would be a chemical
change?
A.
B.
C.
D.
Crushing a rock
Iron rusting
Ice melting
Separating ink dyes by chromatography
Introduction to Matter
Which of the following would be a physical change?
A. Burning a fuel
B. Separating the water into hydrogen and oxygen gas with
electrolysis
C. Liquid water freezing to form ice
D. Silverware becoming tarnished
Introduction to Matter
Which of the following can be used to identify an
unknown substance?
A.
B.
C.
D.
The density of the substance.
The melting point of the substance.
How reactive the substance is.
All of the above are ways to identify the unknown
substance.
Introduction to Matter
Noggin Knockers
(8 points: 1-5 = 1 pt. each, 6 = 3 pts. for any 3 of the
5 signs listed)
1. Chemical Change
2. Physical Change
3. Chemical Change
4. Physical Change
5. Chemical Change
6. Light, heat, bubbles/fizzing, solid forming, color change
Introduction to Matter
Learning Objective
1. Explain how changes in matter are related to changes in
energy.
Introduction to Matter
Cold Compress Lab: Consumer Science
Scenario: You are working for a company that makes cold compresses for injuries.
Determine which substance would make the best cold pack based upon cost,
health hazards, and effectiveness. Note that Tf is the final temperature while
Ti is the initial temperature in the table on the next slide.
1.
Record the initial temperature of the water in the PLASTIC CUP and then add
50 mL to the graduated cylinder.
________oC
2.
Using the beaker and the balance, add exactly 6.0 g of the substance to the
BEAKER on your tray. Hint: Use the Zero button on the balance.
3.
Add the water to the beaker, stir the mixture with the thermometer, & measure
the final temperature (biggest change).
________oC
4.
Record the final temperature and find the temperature change for your chemical.
________oC - ________oC = ________oC (It may be negative)
5.
Gather the remaining data from other groups to finish the table on the next slide.
Then complete the discussion and conclusion.
Introduction to Matter
Data Table
Substance
Temperature
Change (o C)
Tf - Ti
Colder or
Warmer?
Health Hazards
Cost per 100 g
Ammonium
nitrate
Strong oxidizer,
slightly toxic by
ingestion, body tissue
irritant
$5.70
Ammonium
chloride
Slightly toxic by
ingestion
$5.20
Strong oxidant, fire and
explosion risk when
heated, skin irritant
$7.20
Slightly toxic by
ingestion
$4.05
Slightly toxic
$7.50
Irritates eyes and
respiratory track
$5.65
Potassium nitrate
Potassium
chloride
Calcium chloride
Magnesium
Sulfate
(Epsom Salt)
Introduction to Matter
Discussion & Conclusion
Discussion: Discuss which substances should definitely not
be used in cold packs and WHY (use evidence from your
data table). Also, discuss the advantages and
disadvantages of all of the other remaining substances).
In a nutshell: In your discussion you should be discussing
the pros and cons of each substance in terms of the
effectiveness (temp. change), health hazards, and cost.
Conclusion: Identify the best cold pack substance and
briefly explain why it’s the best in terms of effectiveness,
health hazards, and cost).
Introduction to Matter
Learning Objective
1. Explain how changes in matter are related to changes in
energy.
Introduction to Matter
Matter and Energy
When matter undergoes a change, a change in energy
also occurs. This change is sometimes not noticeable,
but some changes in energy are easier to observe.
An endothermic change is when matter absorbs energy
from its surroundings, such as the heat needed to melt
ice. A real world example would be the use of a cold
compress.
An exothermic change is when matter gives off energy
to its surroundings, such as explosions. A real world
example would be the heat given off when fuel burns.
Introduction to Matter
Every change in matter is accompanied by a change
in
A.
B.
C.
D.
mass
energy
volume
matter
Introduction to Matter
The two types of energy changes are
A.
B.
C.
D.
Small and Massive
Chemical and Physical
Out-thermic and In-thermic
Endothermic and Exothermic
Introduction to Matter
What’s the difference between an endothermic and
an exothermic change?
A. They both absorb energy.
B. They both give off energy.
C. An endothermic change gives off energy while an
exothermic change absorbs energy.
D. An exothermic change gives off energy while an
endothermic change takes in or absorbs energy.
Introduction to Matter
What’s an easy way to tell the difference between an
endothermic change and an exothermic change?
A. If it feels cold, then it is most likely an endothermic
change while an exothermic change would feel warm.
B. If it feels cold, then it is most likely an exothermic change
while an endothermic change would feel warm.
C. There is no easy way to tell!
D. They both give off heat.
Introduction to Matter
Which of the following is an endothermic change?
A.
B.
C.
D.
Burning a fuel
Fireworks exploding in the sky
Mixing a solid with water where the temperature goes up.
Mixing a solid with water where the temperature goes
down.
Introduction to Matter
Which reaction shown in the graph below would
indicate that an exothermic change is taking place?
A.
B.
C.
D.
E.
Reaction A
Reaction B
Reaction C
Reactions A & B
Neither Reaction
Introduction to Matter
If you burn some gasoline in your brand new car,
then what type of energy change and change in
matter occurred?
A.
B.
C.
D.
Exothermic & Physical Changes
Exothermic & Chemical Changes
Endothermic & Chemical Changes
Endothermic & Physical Changes
Introduction to Matter
Is the following a chemical change?
A. Yes
B. No
Introduction to Matter - Changes in Matter
Conserving Matter
The idea of atoms explains the law of conservation of matter.
For every molecule of methane that burns, two molecules of
oxygen are used. The atoms are rearranged in the reaction,
but they do not disappear.
Introduction to Matter - Changes in Matter
Conserving Matter Activity
Click the Active Art button to open a browser window and
access Active Art about conserving matter.
Introduction to Matter - Changes in Matter
Comparing Energy Changes
A student observes two different
chemical reactions, one in
beaker A, and the other in
beaker B. The student measures
the temperature of each reaction
every minute. The student then
plots the time and temperature
data and creates the following
graph.
Introduction to Matter - Changes in Matter
Comparing Energy Changes
Reading Graphs:
What do the numbers on the
x-axis tell you about the
length of the experiment?
The experiment lasted for 10
minutes.
Introduction to Matter - Changes in Matter
Comparing Energy Changes
Comparing and Contrasting:
How did the change in
temperature in beaker B differ
from that in beaker A?
The temperature decreased
in beaker B, but increased in
beaker A.
Introduction to Matter - Changes in Matter
Comparing Energy Changes
Interpreting Data:
Which reaction is exothermic?
Explain your reasoning.
Reaction A is exothermic
because thermal energy was
released, causing an increase
in temperature.
Introduction to Matter - Changes in Matter
Comparing Energy Changes
Calculating:
Which reaction results in a
greater change in
temperature over time?
Reaction A
Introduction to Matter - Changes in Matter
Relating Cause and Effect
A cause makes something happen. An effect is what
happens. As you read, identify two effects caused by a
chemical change. Write the information in a graphic
organizer like the one below.
Effects
Cause
A single substance
changes to one or more
other substances.
Chemical change
Two or more substances
combine to form different
substances.
Introduction to Matter - Changes in Matter
Chemical Change
Click the Video button to watch a movie about chemical
change.
Introduction to Matter
End of Section:
Changes in
Matter
Introduction to Matter
Noggin Knockers (9 pts.- Hwk. grade)
1. Physical, still the same substance after the change. (2
points)
2. Drying wet clothes and cutting snowflakes = Physical
Change, Burning oil = Chemical change (3 points total, 1
pt. per part)
3. Any 3 of the following: bubbling/fizzing, heat, light,
color change, and solid forms (3 points)
4. Add energy/heat to it (1 point)
Introduction to Matter
Learning Objectives
1. Identify the various forms of energy.
2. Identify and explain energy transformations.
Introduction to Matter
Forms of Energy
Energy = Ability to do work or cause change
There are many forms of energy related to changes in matter. These forms
of energy include…
Mechanical (parts moving around)
Sound (energy from noise)
Kinetic (energy of motion)
Potential (stored energy)
Chemical (energy from chemicals such as compounds in food)
Electromagnetic (energy from light such as solar energy)
Electrical (energy from electric current)
Thermal energy (energy dealing with heat)
- Energy
Transformations and Conservation
Introduction
to Matter
Energy Transformations
Most forms of energy can be transformed into other forms.
- Energy
and Fossil Fuels
Introduction
to Matter
Use of Fossil Fuels
Fossil fuels can be burned to release the chemical energy
stored millions of years ago.
Introduction to Matter
Energy Transformations
For anytime you eat food to go play a sport, what energy
transformation takes place?
Chemical energy into kinetic or mechanical
What type of energy starts the process of photosynthesis?
Solar (a form of electromagnetic energy)
So, is photosynthesis an endothermic or exothermic
process? Why?
Endothermic, absorbs energy from the sun
Since photosynthesis creates sugars to be used for energy,
then these sugars are a form of __________ energy.
Chemical Energy
Introduction to Matter
Energy Transformations
Determine the energy transformations that occur for the following examples:
Using a battery to power the remote control
Chemical (w/in battery) into electrical energy (using remote)
A car speeding
Chemical (fuel) into thermal (fuel burning) into Mechanical (car moving)
A windmill used to power city lights
Kinetic energy (from wind) into Mechanical (blades spinning) into electrical energy (for the
lights) into electromagnetic (lights)
Eating food and then playing outside
Chemical (food) into kinetic or mechanical (playing)
Solar panels used to power a fan
Solar/electromagnetic (from the sun) into electrical (fan) into mechanical (fan blades
move)
Furnace burns coal in a home
Chemical (coal) into thermal energy (heat for home)
Introduction to Matter
Just like you heard from the Transformers movies,
energy is not created or destroyed, it is
A.
B.
C.
D.
transformed.
different.
I’m not allowed to watch those movies.
the same.
Introduction to Matter
If you perform a chemical reaction that produces
heat, then what energy transformation took place?
A.
B.
C.
D.
Chemical into Electromagnetic energy
Chemical into Thermal energy
Thermal into Chemical energy
Kinetic into Thermal energy
Introduction to Matter
What energy transformation takes place during
photosynthesis?
A.
B.
C.
D.
Chemical energy into solar energy.
Solar energy into thermal energy
Solar energy into kinetic energy
Solar energy into chemical energy
Introduction to Matter
What energy transformations take place to allow
you to use a fan at home? Hint- The burning of
fossil fuels helps to produce the electricity you use
at your home.
A.
B.
C.
D.
Electrical into Kinetic energy
Chemical into Mechanical into Electromagnetic energy
Electrical into Chemical
Chemical into Thermal into Electrical into Mechanical
energy
Introduction to Matter
Substances that CANNOT be broken down
chemically into other substances are
A.
B.
C.
D.
elements
compounds
mixtures
Compounds & mixtures
Introduction to Matter
Pure sugar (C6H12O6) and salt (NaCl) are examples
of
A.
B.
C.
D.
elements
compounds
mixtures
Impure substances
Introduction to Matter
Coffee consists of several substances that are NOT
chemically combined, so coffee would be a(n)
A.
B.
C.
D.
pure substance
element
compound
mixture
Introduction to Matter
Compounds have the SAME properties as the
elements that make them up.
A. True
B. False
Introduction to Matter
If you traveled to the moon,
A.
B.
C.
D.
both your mass and weight would stay the same.
your weight would stay the same but your mass would change.
your mass would stay the same but your weight would change.
Both would change.
Introduction to Matter
Which of the following would float in water?
A. Aluminum (D = 2.7 g/mL)
B. Gasoline (D = 0.73 g/mL)
C. Mercury (D = 13.5 g/mL)
Introduction to Matter
If you heat a solid and measure the temperature at
which it melts, you are measuring a(n)
A. atomic property.
B. physical property.
C. chemical property.
Introduction to Matter
If you describe aluminum as a metal that reacts to
acid, then you are describing a
A. State of matter.
B. Physical property
C. Chemical property
Introduction to Matter
An example of a chemical change would be
A.
B.
C.
D.
E.
A light stick producing blue light
Filtering sand out from a sample of water
Melting chocolate
All of the above are examples of chemical changes.
Choices A and C are correct.
Introduction to Matter
Homework: p. 33- 1a, 1b, 2a, 2b, 2c
(2 pts. each for 10 pts.)
1a- Kinetic, potential, chemical, electromagnetic, electrical, & thermal
(mechanical, sound, wind, etc.)
1b- Book lying on desk = potential energy, Falling book = kinetic
energy
2a- Chemical energy is transformed into a different form of energy.
2b- Paper burning = electromagnetic & thermal (heat and light), where
it comes from = chemical energy stored in the paper
2c- Electromagnetic/solar from the sun is converted into chemical
energy by plants. You eat plants or animals that eat plants and
chemical energy is converted into mechanical/kinetic energy, which
enables you to turn the page.
Introduction to Matter - Energy and Matter
Identifying Main Ideas
As you read the section “Forms of Energy,” write the main
idea in a graphic organizer like the one below. Then write
three supporting details that give examples of the main idea.
Main Idea
There are many forms of energy.
Detail
Detail
Detail
Chemical energy is
the energy stored in
the chemical bonds
between atoms.
Electromagnetic
energy travels
through space as
waves.
Electrical energy is
the energy of
electrically charged
particles moving from
one place to another.
Introduction to Matter - Energy and Matter
Links on Matter and Energy
Click the SciLinks button for links on matter and energy.
Introduction to Matter
End of Section:
Energy and
Matter
Introduction to Matter
Graphic Organizer
Matter
undergoes
includes
Elements
Compounds
Heterogeneous
Mixtures
Physical
change
Chemical
change
may be
such as
such as
Crushing
Combustion
Homogeneous
Introduction to Matter
End of Section:
Graphic Organizer