Introduction to Matter Describing Matter Measuring Matter Changes in Matter Energy and Matter Table of Contents

Introduction to Matter

Describing Matter

Measuring Matter

Changes in Matter

Energy and Matter

Table of Contents


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.

- Describing Matter


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Introduction to ChemistryHindenburg-Hydrogen 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.


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).


Learning ObjectivesChemistry studies matter and how it changes. The 3 types of 3 types of

mattermatter are Elements, Compounds, and Mixtures.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


Elements, Compounds, & MixturesGoal: Determine which dish represents the particlesparticles of an element, which one represents the particlesparticles of a compound, and which one represents the partsparts 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]


ElementsElement- 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.


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 letterONE capital letter or ONE ONE capital and ONE lowercasecapital 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


Learning Objective

2. Explain the relationship between elements and compounds (& be able to identify examples of each).


Demonstration of Compound FormationBig 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 reactiveSodium 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.


Properties: Compounds & Their ElementsCompound/ Properties

Elements in the Compound

Physical Properties of the Elements

Chemical Properties of the Elements

CaCl2

White Solid, Ice Melt Salt

Ca = Calcium

Cl = Chlorine

Calcium- Dark, dull gray metal

Chlorine- yellowish-green gas

Calcium- reacts to water

Chlorine- Toxic gas

MgO

White Solid, Drying Agent

Mg = Magnesium

O = Oxygen

Magnesium- Shiny gray metal

Oxygen- colorless gas

Magnesium- reacts to hot water

Oxygen- reacts to iron & other substances

KCl

White Solid, Salt Substitute

K = Potassium

Cl = Chlorine

Potassium- dull gray metal

Chlorine- yellowish-green gas

Potassium- highly reactive to water

Chlorine- Toxic gas


CompoundsCompounds- 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)

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.

NH3

Elements

Compounds

NH3


Compound Review: Think-Pair-Share1. 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.


Learning Objective



CSI BAMS: Ink Analysis

Jan. 13, 2015


Crime Scene: Main OfficeTuesday 1/13/15 8:01 A.M.


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.


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.


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.


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.


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.


Separating the Ink Mixture1. 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.


What Is Ink?

Several organic dyes - blue, red, black, etc. (This can form an ink "fingerprint.")

Tags that signify the manufacturing year - isotopes


Why is ink important forensically?

Fraud cases

Embezzlement

Theft

Kidnapping and Ransom

Threats

Documentation


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.


What is chromatography?

• Qualitative analysis.

• Separates mixtures into individual parts.


Learning Objective



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?


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 w/o saltsalt) and explain them to the Professor.

Explain how you can separate the parts of each type of mixture.

Heterogeneous- pick out the parts somehowHomogeneous- boil off the water, let it evaporate

Are the parts of a mixture chemically bonded together?NO


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.


Correctly identify what each diagram represents.

A. 1- compound, 2- compound, 3- mixture

B. 1- element, 2- compound, 3- mixture

C. 1- mixture, 2- compound, 3- element

D. 1-element, 2- mixture, 3- compound

1 32


A pure substance that cannot be broken down is called a(n)

A. mixture

B. compound

C. element

D. Mr. Nye


Determine the number of parts for each element in the compound Calcium Sulfate (CaSO4).

A. 0 calcium, 0 sulfur, 4 oxygen

B. 1 calcium, 4 sulfur, 4 oxygen

C. 1 Calcium, 1 sulfur, 4 oxygen

D. 4 calcium, 4 sulfur, 4 oxygen


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.


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.


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.


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 outC. Iron filings- dissolve in water, salt- dissolve in water then

filterD. Iron filings- use a magnet, salt- dissolve it in water then

filter


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.

- 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.

- Describing Matter


Building VocabularyA 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.

- Describing Matter

Key Terms: Examples:matter Matter is anything that has mass and takes up space.

chemistry Chemistry is the study of the properties of matter and how matter changes.

substance In chemistry, a substance is a single kind of matter that is pure, meaning it always has a specific makeup—or composition—and a specific set of properties.

physical property A physical property is a characteristic of a pure substance that can be observed without changing it into another substance.

Key Terms: Examples:chemical property

element

atom

chemical bond

A chemical property is a characteristic of a pure substance that describes its ability to change into different substances.

An element is a pure substance that cannot be broken down into any other substances by chemical or physical means.

An atom is the basic particle from which all elements are made.

When atoms combine, they form a chemical bond, which is a force of attraction between two atoms.

Key Terms: Examples:molecule

compound

chemical formula

In many cases, atoms combine to form larger particles called molecules—groups of two or more atoms held together by chemical bonds.

A compound is a pure substance made of two or more elements chemically combined in a set ratio.

A compound may be represented by a chemical formula, which shows the elements in the compound and the ratio of atoms.

Key Terms:mixture

Examples:

heterogeneous mixture

homogeneous mixture

solution

A mixture is made of two or more substances—elements, compounds, or both—that are together in the same place but are not chemically combined.

In a heterogeneous mixture, you can see the different parts.

The substances in a homogeneous mixture are so evenly mixed that you can’t see the different parts.

A solution is an example of a homogeneous mixture.


Links on Describing Matter

Click the SciLinks button for links on describing matter.

- Describing Matter


End of Section:Describing

Matter


Learning Objectives

1. Describe how the density of a material is determined.


Density DemonstrationsD = 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 massesHow does mass affect density (if the volume is the same)?

Heavier mass = Greater Density

Metal Spheres- Constant mass, but different volumesHow 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)


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 compounds2 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.


Making Sense of Density LabProblems (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).

Procedure1. 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 4 different sizes.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.


Density of Colored Cylinders Table (Sample)Color & Size of

Object

(Example below)

Mass (g)

Initial Volume

(mL)Vi

Final Volume (mL)

Vf

Volume Change

(mL)Vf – Vi

Density (g/mL)

D = M/V

Red Cylinder (largest)

Red Cylinder (2nd largest)

Red Cylinder(3rd largest)

Red Cylinder(smallest)

Purple Cylinder(largest)

Purple Cylinder (2nd largest)

Include other Include other 2 sizes2 sizes of 2of 2ndnd object object

too.too.


Analyze & Conclude1. For each objecteach object you tested, compare the density of the largest cylinder with the densities of the smaller ones. Were they mostly similarmostly similar or quite differentquite different? Keep in the mind that the smallest cylinder’s measured density is probably slightly inaccurate.

2. Use your results to explain how density can be used to identify a substance. Guiding Questions: If you have 2 samples of the same substance and one sample is much larger (in mass and volume), will the actual density be different (examine your results if needed)? Why or why not?

3. What are the colors & identities of your twotwo substances?

Substance Density (g/mL)

Maple Wood 0.77

Polypropylene 0.90

Polystyrene 1.03

Nylon 1.15

Acrylic 1.17

Polyurethane 1.23

Phenolic 1.32

Polyvinylchloride (PVC)

1.37

PTFE (Teflon) 2.2

Aluminum 2.71


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.


Analyze & Conclude Examine the densities in the table on the right to determine the composition of the pre-1982 and post-1982 pennies.

1. Write what pre-1982 and post-1982 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


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.


Learning Objectives

2. Identify the units used the amount of space occupied by matter (volume).

3. Determine the difference between weight and mass.


Weight vs. MassWeight 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


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.


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. Determine its mass.

B. Give it to the Professor to examine.

C. Determine its weight.

D. Determine its density.


Why do ice cubes and wooden boats float in water?

A. Wood floats in water, but ice does not.

B. Wood and ice have a density greater than 1.0 g/mL.

C. Ice is lighter than water.

D. Ice and wood both have a density less than 1.0 g/mL.

E. Only ice floats in water, wood is too heavy to float.


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


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. On top of liquid A

B. Between liquids B and C

C. Between liquids C and D

D. On the bottom of the beaker


The amount of matter in an object is its

A. mass

B. volume

C. density

D. temperature


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. What planet am I on now???

B. Weight- stay the same; Mass- stay the same

C. Weight- change; Mass- remain the same

D. Weight- change; Mass- change too


What property of the rock is being measured in the picture below?

A. Temperature

B. Density

C. Volume

D. Mass


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


End of Section:Measuring 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)


Learning Objectives1. 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.


Chemical vs. Physical Changes LabGoal- Identify the following

changes as a chemical or physical change.

Post-lab Questions1. Is chromatography a chemical

or physical change?

2. Identify the following as a chemical or physical property: a) water (as ice) melts at 0oCb) 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?

3. What are at least 3 signs of a chemical change?

Change ObservationsChemical

or Physical Change

Crumpling paper (don’t do) Paper crinkled

Lighting a match (don’t do) Light and heat were given off

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

Bending a light stick (demo)


Changes in MatterIf 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.

- Changes in 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?


Examples of Chemical Change


Which of the following is NOT a likely sign that a chemical change took place?

A. The substance changed in color.

B. Light and heat were produced.

C. Bubbles of gas were formed.

D. A liquid was cooled and changed into a solid.


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.


Which of the following would be a chemical change?

A. Crushing a rock

B. Iron rusting

C. Ice melting

D. Separating ink dyes by chromatography


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


Which of the following can be used to identify an unknown substance?

A. The density of the substance.

B. The melting point of the substance.

C. How reactive the substance is.

D. All of the above are ways to identify the unknown substance.


Noggin Knockers (8 points8 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


Learning Objective

1. Explain how changes in matter are related to changes in energy.


Cold Compress Lab: Consumer ScienceScenario: 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 substancethe 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.


Data TableSubstance 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

Potassium nitrate Strong oxidant, fire and explosion risk when heated, skin irritant

$7.20

Potassium chloride

Slightly toxic by ingestion

$4.05

Calcium chloride Slightly toxic $7.50

Magnesium Sulfate

(Epsom Salt)

Irritates eyes and respiratory track

$5.65


Discussion & ConclusionDiscussion: Discuss which substances should definitely not be used in cold packs and WHY (use evidence from your WHY (use evidence from your data table)data table). Also, discuss the advantages and disadvantages of all of the other remaining substances).

In a nutshellIn 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).


Learning Objective

1. Explain how changes in matter are related to changes in energy.


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.


Every change in matter is accompanied by a change in

A. mass

B. energy

C. volume

D. matter


The two types of energy changes are

A. Small and Massive

B. Chemical and Physical

C. Out-thermic and In-thermic

D. Endothermic and Exothermic


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.


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.


Which of the following is an endothermic change?

A. Burning a fuel

B. Fireworks exploding in the sky

C. Mixing a solid with water where the temperature goes up.

D. Mixing a solid with water where the temperature goes down.


Which reaction shown in the graph below would indicate that an exothermic change is taking place?

A. Reaction A

B. Reaction B

C. Reaction C

D. Reactions A & B

E. Neither Reaction


If you burn some gasoline in your brand new car, then what type of energy change and change in

matter occurred?

A. Exothermic & Physical Changes

B. Exothermic & Chemical Changes

C. Endothermic & Chemical Changes

D. Endothermic & Physical Changes


Is the following a chemical change?

A. Yes

B. No


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.

- Changes in Matter


Conserving Matter Activity

Click the Active Art button to open a browser window and access Active Art about conserving 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.

- Changes in Matter



The experiment lasted for 10 minutes.

Reading Graphs:

What do the numbers on the x-axis tell you about the length of the experiment?

- Changes in Matter



The temperature decreased in beaker B, but increased in beaker A.

Comparing and Contrasting:

How did the change in temperature in beaker B differ from that in beaker A?

- Changes in Matter



Reaction A is exothermic because thermal energy was released, causing an increase in temperature.

Interpreting Data:

Which reaction is exothermic? Explain your reasoning.

- Changes in Matter



Reaction A

Calculating:

Which reaction results in a greater change in temperature over time?

- Changes in Matter


Cause

Effects

Relating Cause and EffectA 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.

Chemical change

A single substance changes to one or more other substances.

Two or more substances combine to form different substances.

- Changes in Matter


Chemical Change

Click the Video button to watch a movie about chemical change.

- Changes in Matter


End of Section:Changes in

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)


Learning Objectives

1. Identify the various forms of energy.

2. Identify and explain energy transformations.


Forms of EnergyEnergy = 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)

Introduction to Matter- Energy Transformations and Conservation

Energy Transformations

Most forms of energy can be transformed into other forms.

Introduction to Matter- Energy and Fossil Fuels

Use of Fossil Fuels

Fossil fuels can be burned to release the chemical energy stored millions of years ago.


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


Energy TransformationsDetermine the energy transformations that occur for the following examples:

Using a battery to power the remote controlChemical (w/in battery) into electrical energy (using remote)

A car speedingChemical (fuel) into thermal (fuel burning) into Mechanical (car moving)

A windmill used to power city lightsKinetic energy (from wind) into Mechanical (blades spinning) into electrical energy (for the

lights) into electromagnetic (lights)

Eating food and then playing outsideChemical (food) into kinetic or mechanical (playing)

Solar panels used to power a fanSolar/electromagnetic (from the sun) into electrical (fan) into mechanical (fan blades

move)

Furnace burns coal in a homeChemical (coal) into thermal energy (heat for home)


Just like you heard from the Transformers movies, energy is not created or destroyed, it is

A. transformed.

B. different.

C. I’m not allowed to watch those movies.

D. the same.


If you perform a chemical reaction that produces heat, then what energy transformation took place?

A. Chemical into Electromagnetic energy

B. Chemical into Thermal energy

C. Thermal into Chemical energy

D. Kinetic into Thermal energy


What energy transformation takes place during photosynthesis?

A. Chemical energy into solar energy.

B. Solar energy into thermal energy

C. Solar energy into kinetic energy

D. Solar energy into chemical energy


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. Electrical into Kinetic energy

B. Chemical into Mechanical into Electromagnetic energy

C. Electrical into Chemical

D. Chemical into Thermal into Electrical into Mechanical energy


Substances that CANNOT be broken down chemically into other substances are

A. elements

B. compounds

C. mixtures

D. Compounds & mixtures


Pure sugar (C6H12O6) and salt (NaCl) are examples of

A. elements

B. compounds

C. mixtures

D. Impure substances


Coffee consists of several substances that are NOT chemically combined, so coffee would be a(n)

A. pure substance

B. element

C. compound

D. mixture


Compounds have the SAME properties as the elements that make them up.

A. True

B. False


If you traveled to the moon,

A. both your mass and weight would stay the same.

B. your weight would stay the same but your mass would change.

C. your mass would stay the same but your weight would change.

D. Both would change.


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)


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.


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


An example of a chemical change would be

A. A light stick producing blue light

B. Filtering sand out from a sample of water

C. Melting chocolate

D. All of the above are examples of chemical changes.

E. Choices A and C are correct.


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.


Main Idea

Detail Detail Detail

Identifying Main IdeasAs 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.

There are many forms of energy.

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.

- Energy and Matter


Links on Matter and Energy

Click the SciLinks button for links on matter and energy.

- Energy and Matter


End of Section:Energy and

Matter


Graphic Organizer

Elements Compounds Physicalchange

Hetero-geneous

Homo-geneous Combustion

undergoesincludes

may be such as such as

Matter

Mixtures Chemical change

Crushing


End of Section:Graphic Organizer

Documents

Introduction to Matter Describing Matter Measuring Matter Changes in Matter Energy and Matter Table of Contents