teacher lab chapter 2

8/17/2019 Teacher Lab Chapter 2

1/31

Teacher Notes 31

States of Matter

What Are Solids, Liquids, and Gases? 39

Modeling Particles !

As Thic" as #one$ 1

#o% &o the Particles in a Gas Mo'e? (

)hanges of State

What #a**ens When +ou reathe on a Mirror? 3

Melting -ce Pre Lab Directed Inquiry Open Inquiry

.9

/ee*ing )ool .3

0ser'ing Suli2ation .

Gas eha'ior

#o% )an Air /ee* )hal" ro2 rea"ing? ..

#o% Are Pressure and Te2*erature 4elated? .5

#ot and )old alloons .6

-t7s a Gas .8

3!

Solids, Liquids, and Gases

TABLE OF CONTENTS


2/31

States of Matter Ans%ering the ig uestion

The activities in this lesson will help students

answer the Big Question by providing opportu-nities to work with substances in different states

and to infer how the particles behave in each

state.

What are Solids, Liquids,and Gases?

-nquir$ ocus Form an Operational Definition —creating a

definition of the terms solid, liquid, and gas by

observing the three states at the same time in aclosed system

Grou* Si:e Individuals or pairs

)lass Ti2e 1 minutes

Alternati'e Materials!i""ing antacid powders are also suitable. They

react far more #uickly than tablets.

Procedure Ti*s1. $se only selt"er-type antacid tablets.

2. Tablet pieces should be relatively uniform in

si"e so they fit easily into the mouth of the

balloon.3 %tudents should use care not to nick or tear

the balloon when inserting the tablet pieces.

4. &ave some students use two tablets and pre-dict what will happen.

5. 'rovide paper towels to clean up any spills.

Ans%ers1. The balloon contained air and was filled

with carbon dio(ide while the tablets were

dissolving. The water in the bottle was about

the same level but with a few specks floating

in it. The tablet pieces disappeared.

2. )ook for answers that include some or all of the following* %olids* bottle+ balloon+ tablets,

)i#uid* water, ases* bubbles in the water+

and the gases that filled the balloon.

3. %ample nswer* %olids keep their shapes.

)i#uids take the shape of their containers.

ases are invisible and can inflate a balloon.

Modeling Particles

;nloc"ing the /e$ )once*t

This activity will help students understand thearrangement of particles in a solid by modeling

how that arrangement contributes to matter

having a definite volume and a definite shape.

-nquir$ ocus Make Models —creating a physical model of asolid and then observing the arrangement of

the particles in it



Safet$/emind students that they should never taste

any materials used in the science classroom.

Ad'ance Pre*aration 01 minutes1. %and should be damp enough to mold+ but

not too wet. If you use brown sugar+ check

that the brown sugar has not dried out.

2. 2utting s#uares of the wa(ed paper before

class will save time.

Procedure Ti*s light tap on the top or side of the cup may

aid in releasing the material from the cup.

Ans%ers1. The grains are closely packed.

2. %ample nswer* The grains are closely

packed and do not move relative to

each other.

3. The sand or sugar grains are not vibrating in

place like the particles in a solid do.

As Thic" as #one$


This activity will help students understand howthe attractions among the particles in a li#uid

affect viscosity.

31

S0L-&S, L-;-&S, AN& GAS


3/31

-nquir$ ocus Draw Conclusions —analy"ing two different li#-

uids to make a statement about their viscosities

Grou* Si:e 'airs


Safet$/emind students that they should never tasteany materials used in the science classroom.

Ad'ance Pre*aration 01 minutes!ill the 3ars in advance. Tall+ narrow 3ars work

best as they allow the bubble that forms when

the 3ars are tipped to travel a greater distance.ny vegetable oil should work well.

Alternati'e Materials

$se clear plastic 3ars to avoid broken glass.2lear corn syrup or clear li#uid soap can be

used as a substitute for honey.

Procedure Ti*s1. Tell students to make sure the lids are tightly

closed before they turn the 3ars upside down.

2. 4ipe up any spills with paper towels.

Ans%ers1. &oney has the greater viscosity.

2. The air bubble in the 3ar of vegetable oil rosefaster than the air bubble in the 3ar of honey.

3. The particles in the vegetable oil have weaker

attractions to each other+ causing the oil toflow faster.

#o% do the Particles in aGas Mo'e?

;nloc"ing the /e$ )once*tThis activity will help students understand the

motion of particles in a gas by illustrating how

the particles in a gas are in constant randommotion+ completely filling the container they

occupy regardless of its si"e or shape.

-nquir$ ocus Make Models —creating a physical representa-

tion of the particles in a gas and then demon-

strating the motion of those particles

Grou* Si:e 'airs


Ad'ance Pre*aration 01 minutes

1. 5ou may want to use scissors to cut the foam packing pieces into smaller pieces prior to

the activity

2. Thin "ipper bags will e(pand more easily

than thick ones when students blow into

them.

Alternati'e Materials6ost small+ puffed cereal can be used in place

of the foam packing.

Procedure Ti*s1. %tudents should not try to seal the bag com-

pletely. They must leave a small space for air to escape.

2. Tell students that gentle blowing on the

straw will prevent the bag from un"ipping.

3. The bag will need to be completely inflated

before the foam pieces start moving around.

Ans%ers1. The foam pieces were in constant motion

and moved in random directions.

2. The foam pieces moved faster when I blew

harder than when I blew gently.

3. The fast motion of the foam pieces models

the particles in a gas at a high temperature.4. The foam pieces would move in random

directions regardless of the si"e of the bag.

In a big bag+ the foam pieces would spread

out to fill the space. In a small bag+ the foam

pieces would be closer together.

)hanges of StateAns%ering the ig uestion


answer the Big Question by allowing them to

observe condensation and sublimation, e(plorehow energy and temperature are related,

observe factors related to changes in states of

matter, and understand the relationship among

gases+ pressure+ and temperature.

32



4/31

What #a**ens When +oureathe on a Mirror?

-nquir$ ocus Develop a Hypothesis —making a testable

statement about the cause of and the factors

influencing condensation on a mirror when

the mirror is breathed upon



Safet$2aution students about the ha"ards of broken

glass if glass mirrors are used.

Ad'ance Pre*aration 07 minutesThe mirrors should be kept in a relatively coollocation to ensure good results. lass mirrors

should be checked for cracks.

Alternati'e Materials6etal mirrors or polished stainless steel cook-

ing pots+ pans+ or lids can be substituted for the

mirrors. 'lastic mirrors do not work well and

should be avoided.

Procedure Ti*sIf students have trouble producing condensa-

tion on their mirrors+ suggest that they hold

their breath for a few seconds before breathingout.

Ans%ers1. The surface of the mirror is clear and shiny.

2. %omething clouded the surface of the mirror.

3. %ample &ypothesis* 4ater vapor in warm

breath condenses on the cool surface of the

mirror+ producing a cloudy appearance. The

water vapor molecules lose energy when they

touch the mirror8s surface+ causing the vapor

to condense to form a li#uid.

4. )ook for answers that state that at greater

distances the water vapor in the breath dis-

perses or cools in the air before it reaches the

mirror8s surface.

Melting -ce


Both Versions This activity will help students

understand energy changes by showing ane(ample in which a substance+ water+ changes

state by absorbing energy from the surround-

ings. %tudents will learn that absorbed energy

causes the temperature of the surroundings to

decrease.

Ans%ers=Pre La

Both Versions:

1. They will take the same amount of timeto melt.

2. If one ice cube absorbs energy faster+ thetemperature of the water in that cup will

decrease more #uickly than the temperature

in the other cup.

-nquir$ ocus

Directed Inquiry:

Predict —confirming or re3ecting the originalhypothesis based on the analysis and inter-

pretation of time and temperature data col-

lected as ice melts in surroundings of different

temperature

Open Inquiry:

Predict —using prior knowledge to make aneducated guess about which ice cube will melt

faster

nterpret Data —recording and analy"ing mea-

surement data and observations to e(plain the

melting process

nfer —using data to draw conclusions about

the thermal energy source used to melt the ice

Grou* Si:e

Directed Inquiry 'airs or groups

Open Inquiry roups

)lass Ti2eBoth Versions 9 minutes

Safet$

Both Versions:

/emind students that thermometers are fragile

and should be used with care. They should not be used to stir the water and ice mi(tures.

33



5/31

Ad'ance Pre*aration 017 minutesBoth Versions:

1. 6ake enough ice cubes for the class. !or

the :irected In#uiry version+ the ice cubes

should be small and of uniform si"e. !or the;pen In#uiry version+ the ice cubes should be small but of varying si"es.

2. &eat water or use warm tap water.

Procedure Ti*sDirected Inquiry:

1. If possible+ provide two thermometers per

station so students do not have to move

thermometers from one cup to the other.

2. If students will use probeware+ demonstrate

its use.

3.


6/31

Open Inquiry:

1. %ample nswer* I predicted that the ice cube

in warm water would melt faster+ and that is

what happened in the e(periment.

2. %ample nswer* The temperature changedthe most in the cup with warm water. It took

9 minutes+ seconds for the ice cube in the

warm water to melt. The final temperature

was 9C=2. The ice cube in the room-tem-

perature water took 7 minutes+ seconds to

melt+ with a final temperature of 9=2.

3. The source of energy was the thermal energy

of the water in each cup.

4. )ook for answers that describe the flow of

energy from the hotter substance to the

colder substance. %ample nswer* Thermal

energy from the stove burner is transferred

to the soup particles through the metal pot.

4hen the warm soup is placed in the refrig-

erator+ heat will flow from the soup to the air

in the refrigerator.

5. %ample nswer* I would put a small amount

of water in a graduated cylinder. I would

record the volume of water in the cylinder

before and after I put each ice cube in it.

The difference in the volume would be the

volume of the ice cube. Then I could cal-

culate how long it took to melt per unit of

volume 0m).

Ans%ers=Post LaDirected Inquiry:

1. %tudents should generally see the same results.

:iscrepancies could occur from using differ-

ent-si"e ice cubes+ different amounts of water+

or water of different temperatures. 6uch will

depend on how much heat the cups absorb

from or release to the environment. %o if the

cups differ+ so might the results.

2. If the water is not stirred+ a region of cold

water will develop around the ice cube and

melting will be slowed.

3. %tudents should describe what they learned by observing the difference in temperature

change and melting time between the two

cups. !or e(ample+ the difference in temper-

ature change and melting time can be attrib-

uted to the different amount of thermal

energy available in the two cups. %tudents

may still want to know why the melting ice

remains at =2. %ome students may wonder

why there is a difference in temperature and

melting time+ considering that ice cubes of

e#ual si"e must absorb the same amount of

thermal energy in order to melt.

Communicate —%ample nswer*


7/31

/ee*ing )ool


This activity will help students understand the process in which a li#uid evaporates to form

a gas. %tudents will infer that evaporation

absorbs energy from the surroundings and that

some substances evaporate faster than others.

-nquir$ ocus nterpret Data —analy"ing and drawing conclu-

sions from the way temperature data changeover time as two different li#uid substances

evaporate

Grou* Si:e 'airs or groups


Safet$1. 2aution students that thermometers are

fragile. %tudents should wear safety goggles.

2. /ubbing alcohol is flammable. 6ake surethere are no open flames.

Ad'ance Pre*aration 01 minutes1. !or rubbing alcohol+ use D7 percent

isopropyl alcohol. %ome rubbing alcohol is

E9 percent isopropyl alcohol+ which does not

evaporate as rapidly.

2. )ay pairs of thermometers on paper towelsat lab stations.

Ans%ers1. %ample nswer* The rubbing alcohol evapo-

rated faster because the temperature of the

thermometer with the alcohol-soaked gau"e

decreased more rapidly than the temperature

of the thermometer with the water-soaked

gau"e.

2. )ook for answers that suggest that the rub-

bing alcohol evaporates rapidly+ absorbingheat from the patient8s body.

0ser'ing Suli2ation

;nloc"ing the /e$ )once*tThis activity will help students identify e(am-

ples of sublimation and condensation.

-nquir$ ocus nfer —observing what happens when dry ice is

placed in water and inferring what changes of

state are occurring

Grou* Si:e 'airs

)lass Ti2e minutes

Safet$1. :o not handle dry ice with bare hands. It

damages skin tissue on contact.

2. 4ear safety goggles+ a lab apron+ and leather

gloves when handling dry ice.

3. $se forceps to place a pea-si"ed piece of dry

ice into each flask.

4. 2aution students not to touch dry ice and to

use care when handling glassware to avoid

breakage.

Ad'ance Pre*aration 017 minutes1. ;btain dry ice from a local supplier or from

a scientific supply house+ ice cream whole-

saler+ or compressed gas dealer.

2. :o not store dry ice in an airtight container.

3. )eave a window open in your car if you have

dry ice in the car.

4. :ry ice is usually sold in blocks. $se a ham-mer to carefully break off pea-si"ed pieces

of dry ice. 4ear safety goggles+ a lab apron+

and leather gloves when breaking the dry ice.6ake sure students are not in the area whenyou are breaking up the dry ice.

Alternati'e Materials 7-m) beaker or larger can be used instead

of the


8/31

Gas eha'ior Ans%ering the ig uestion


answer the Big Question by demonstratingthe relationship among gases+ pressure+ and

temperature.

#o% )an Air /ee* )hal"ro2 rea"ing?

-nquir$ ocus nfer —using prior knowledge or e(perienceto make a statement that e(plains how the air

trapped in bubble wrap can prevent an ob3ect

from being broken when the ob3ect is droppedonto a hard surface

Grou* Si:e 'airs


Safet$2aution students to use care when getting onor off the chair.

Ad'ance Pre*aration 01 minutes2ut the wa( paper or plastic wrap and the bub-

ble wrap into appropriately si"ed sheets. $sing

bubble wrap with small bubbles+ of about 1 cm

diameter+ works better than bubble wrap withlarge bubbles.

Procedure Ti*s1. %uggest that students drop the chalk at a

slight angle relative to the floor.

2. ;ne student should act as a GspotterH to pre-

vent the other student from falling off the

chair.

Ans%ers1. The unwrapped chalk broke when it was

dropped and when it was wrapped in wa(ed

paper or plastic wrap. The chalk did not break when it was wrapped in bubble wrap.

2. )ook for answers that include some under-standing of air particles and how they com-

press together on impact+ cushioning the

chalk and absorbing the force of impact.

#o% Are Pressure andTe2*erature 4elated?

;nloc"ing the /e$ )once*tThis activity will allow students to observe how

temperature affects the pressure of a gas at con-

stant volume.

-nquir$ ocusInfer—suggesting a possible e(planation or

drawing a conclusion about a basic property

of gases—that is+ when the volume is held con-

stant+ gas pressure increases when temperature

increases

Grou* Si:e 'airs

)lass Ti2e minutes

Safet$%tudents should use caution with hot water.

Ad'ance Pre*aration 017 minutesThe activity will take less time if the baths are

set up ahead of time.

Alternati'e Materials&ollow+ gas-filled playground balls may also be

used. In addition to comparing s#uee"ing force+

students can compare how well the hot and

cold balls bounce.

Procedure Ti*s1. 2heck to be sure that caps will seal so that

the bottles are airtight.

2. $se plastic bins+ dishpans+ or tubs for the

ice bath and the hot water bath. $se hot tap

water for the hot water bath.

Ans%ers1. The temperature increased.

2. %tudents should infer that the pressure of

the air inside the bottle increased+ because it

takes more force to s#uee"e the bottle.

3. %ample nswer* &ot air molecules movefaster than cold air molecules. The faster gas

particles move+ the more fre#uently they col-

lide with the walls of their container+ increas-

ing the force+ or pressure+ on the inner walls

of the container.

37



9/31

#ot and )old alloons


This activity will help students understand thatthe volume of a gas increases due to increased

molecular motion as the temperature of the gas

increases.

-nquir$ ocusO&serve —using senses to gather information as

two balloons containing the same volume of air

at room temperature are cooled and heated

Grou* Si:e 'airs or groups


Materials1. $se small party balloons that are roughly

spherical when inflated.

2. $se plastic dishpans or similar tubs for water

baths.

Safet$2heck the temperature of hot tap water and

regulate it so that the warm water baths do not

e(ceed 7=2.

Ad'ance Pre*aration 017 minutes%et up hot and ice-cold water baths. !or safety+

the warm water baths should not e(ceed 7=2.

Procedure Ti*s1. Tell students to stretch the balloons several

times to make them easier to blow up.

2. The difference in volume for balloons at =2

and 7=2 is only about 1C+ so students

should compare the balloons #uickly after

removing them from the baths. %tudents

could wrap a piece of string around the

circumference of the balloons and mark it

before the balloons are heated or cooled.

Then they could #uickly wrap the same piece

around the balloons after they are removed

from the baths. $sing the string emphasi"esthe change in si"e.

Ans%ers1. %tudents should observe that the balloon in

the cold bath is smaller than the one in the

warm bath.

2. %tudents should find that the balloons

returned to e#ual si"e as they warmed or

cooled to room temperature.

3. %ample nswer* &eating increases molecular

motion and causes air molecules to strike thewalls of the container more often. Because

the wall of the balloon is fle(ible+ the mol-

ecules push it out to a larger volume. The

effect in the cold balloon is 3ust the opposite

because molecular motion slows down with

a decrease in temperature.

-t7s a Gas>


This activity will help students understand therelationship between gas volume and pressure

by observing how the volume of a gas changesas pressure increases.

-nquir$ ocus Draw Conclusions —analy"ing the relationship

between the pressure e(erted on a gas and the

volume occupied by the gas and then concluding

that the volume occupied by a gas is inversely

proportional to the pressure applied to the gas

Grou* Si:e 'airs

)lass Ti2e 17 minutesAd'ance Pre*aration 01 minutes1. The plungers of the syringes must move

freely or results will be poor.

2. )ubricate sticky syringe plungers with sili-cone grease. :o not use petroleum-based

grease+ as it will dissolve the rubber plunger.

Procedure Ti*s1.


10/31

Name Date Class

What Are Solids, Liquids, and Gases?&ow do you distinguish one state of matter from another? In this activity+

you will observe the three states of matter. 5ou will then form your own

definition of each state based on the physical properties that you observe.

-N;-4+ 0);S or2 an 0*erational &efinition

Procedure

1 Put on your safety goggles. Break an antacidtalet into t!ree or four "ieces. Place t!em inside alarge# uninflated alloon.

( Fill a $%L "lastic ottle aout !alf&ay &it! &ater.Stretc! t!e mout! of t!e alloon o'er t!e to" of t!e

ottle# taking care to kee" t!e talet "ieces insidet!e alloon.

3 Lift t!e alloon and (iggle it so t!e talet "ieces fallinto t!e ottle. Oser'e &!at !a""ens for ) minutes.

*emo'e t!e alloon and e+amine t!e contents of t!e alloon and of t!e ottle.

. Dis"ose of t!e contents in t!e ottle and t!e alloon in t!e area designated yyour teac!er. ,as! your !ands &it! soa".

Thin" -t 0'er

:escribe the contents of the balloon and of the bottle in %tep J.

Identify e(amples of the different states of matter—solids+ li#uids+ and gases—that

you observed in this activity.

:efine each of the three states of matter in your own words.

3*

STAT


11/31

Name Date Class

Modeling ParticlesThe arrangement of the particles causes a solid to have a definite shape and

volume. In this activity+ you will make a model of the particles in a solid.

-N;-4+ 0);S Ma"e Models

Procedure

1 Put on your safety goggles. Place dam" sandor ro&n sugar into t!e small cu". 0se t!e s"oon to"ack t!e sand or sugar 'ery tig!tly in t!e cu". Com%"letely fill t!e cu" and le'el t!e surface.

( Carefully turn t!e cu" u"side do&n on t!e &a+ "a"er to release t!e contents &it!out disturing t!e s!a"e

of t!e sugar or sand.

3 0se t!e magnifying lens to oser'e t!e grains of sand or sugar.

Thin" -t 0'er

&ow are the grains of sand or sugar arranged?

4hy do the sand or sugar grains model the particles in a solid?

4hat property of the particles in a solid do the sand or sugar grains not show?

4+

STAT


12/31

Name Date Class

As Thic" as #one$Kiscosity measures a li#uid8s resistance to flow. It is directly related to the

attractions between particles in the li#uid. )i#uids with a high viscosity

flow more slowly than li#uids with a low viscosity.

-N;-4+ 0);S &ra% )onclusions

Procedure

1 Otain ) (ars from your teac!er1one containing!oney and one containing 'egetale oil.

( Place ot! (ars on a tale. C!eck t!at t!e lids aretig!tly sealed.

3 Turn ot! (ars u"side do&n at t!e same time.Oser'e &!at !a""ens.

Turn t!e t&o (ars rig!t%side u" and again oser'e&!at !a""ens.

Thin" -t 0'er

4hich li#uid has the greater viscosity?

4hat evidence led you to this conclusion?

In which li#uid do the particles have weaker attractions to each other?


13/31

Name Date Class

#o% &o the Particles in a Gas Mo'e?The particles in a gas spread apart and fill all available space. In this

activity+ you will create a model to show how the particles in a gas move.

-N;-4+ 0);S Ma"e Models

Procedure

1 O"en a 2uart%sied "lastic i""er ag. Place a!andful of foam "ieces into t!e ag3 "ut a stra&into t!e ag so t!at aout )45 cm of t!e stra& isinside t!e ag. T!en i" t!e ag closed lea'ingaout !alf a centimeter uni""ed.

( 6old t!e ag at t!e i""er &!ere t!e stra& is inserted

and use t!e stra& to lo& gently into t!e ag.Oser'e t!e motion of t!e foam "ieces.

3 Blo& a little it !arder and oser'e &!at !a""ens.

Thin" -t 0'er

$se the terms constant and random to describe the motion of the foam pieces

when you blew into the bag.

&ow did the motion of the foam pieces change when you blew harder into the bag?

4hich measurement—pressure+ temperature+ or volume—is the motion of the

foam pieces modeling when you blew harder into the bag?


14/31

Name Date Class

What #a**ens When +ou reatheon a Mirror?2hanges of state happen when energy is added to a material or when amaterial loses energy. In this activity+ you will observe a change of state and

form a hypothesis to e(plain why it happened.

-N;-4+ 0);S &e'elo* a #$*othesis

Procedure

1 Pick u" t!e !and mirror. 0se a dry clot! to cleant!e surface of t!e mirror. *ecord t!e a""earance of t!e mirror7s surface.

( 6old t!e mirror aout $8 cm from your face. Breat!eout of your mout! to&ard t!e mirror7s surface.

3 9ee" reat!ing and mo'e t!e mirror closer to your face.Sto" mo'ing t!e mirror &!en your reat!ing "roducesa 'isile c!ange on t!e mirror. Oser'e &!at !a""ens anddescrie your oser'ations.

Thin" -t 0'er

:escribe the appearance of the mirror in %tep 1.

4hat did you observe in %tep 9?

4rite a hypothesis to e(plain your observation in %tep 9. 4hy did that happen?

4hy did you get different results when the mirror was held at greater distances

from your face?

43

)#ANG


15/31

Name Date Class

La -n'estigation

Melting -ce4e'ie%ing )ontent

The change in state from a solid to a li#uid is called

melting. In most pure substances+ melting occurs at aspecific temperature called the melting point. The melting

point of water is =2. :uring melting+ solid water 0ice

absorbs energy from its surroundings. s a result+ thewater molecules overcome the strong attractions that hold

them in place in the ice crystal. ;nce the molecules are free+

they can slide past one another becoming li#uid water.The temperature remains at =2 as the ice melts. The

temperature of the ice8s surroundings decreases as thermal

energy is absorbed by the melting ice.

In this lab+ you will compare the melting rate of two icesamples when they are in contact with cooler water and

warmer water. 5ou will then use your observations to draw

conclusions about energy changes that take place whenmatter changes state.

4e'ie%ing -nquir$ ocus

fter e(perimenting to test a hypothesis+ the ne(t step is to draw

conclusions. 4hen you draw conclusions you confirm or deny the

original hypothesis based on the analysis and interpretation of datacollected in the e(periment. ;ften+ repeated trials are needed. In

this e(periment+ you will record temperature changes and the timeneeded for melting.

'review the )ab Investigation and answer the #uestions in thespace provided.

44

)#ANG


16/31

Name Date Class

Melting -ceProle2

6o& does t!e tem"erature of an ice cue7s surroundingsaffect t!e rate at &!ic! t!e ice melts:

L1 ;n t!is acti'ity# you &ill com"are t!e melting rates of

t&o ice cues &!en eac! is in a different%tem"eratureli2uid. *ead t!e follo&ing "rocedure. Based on your o&n e+"erience# "redict &!ic! ice cue &ill melt faster.,rite your "rediction elo&.

( Fill a cu" !alf&ay &it! &arm &ater -aout C toC/. Fill a second cu" to t!e same de"t! &it! &ater at room tem"erature.

3 ?easure t!e tem"erature of t!e &ater in eac!cu". ;f you are using a tem"erature "roe# see your teac!er for instructions.

*ecord t!e tem"eratures in t!e data tale on t!ene+t "age.

. Otain t&o ice cues t!at are as close to t!e same sie

as "ossile.

5 Place one ice cue in eac! cu". As soon as t!e icemeets t!e &ater# egin timing &it! a sto"&atc! or aclock &it! a second !and.

6 @ently stir eac! cu" &it! a "lastic s"oon until t!e ice !ascom"letely melted. Oser'e ot! ice cues carefully.

8 At t!e moment one of t!e ice cues is com"letelymelted# record t!e time and t!e tem"erature of t!e&ater in t!e cu".

45

)#ANGC

Procedure


17/31

Name Date Class

La -n'estigation

9 Continue stirring until t!e second ice cue melts. *ecord its melting time and t!e&ater tem"erature.

46

)#ANG


18/31

Name Date Class

La -n'estigation

Anal$:e and )onclude

&ra% )onclusions 4as your prediction in %tep 1 supported by the

results of the e(periment?


19/31

Name Date Class

La -n'estigation

Melting -ce

&ra% )onclusions 2ompare your results with the results of other

groups. ive reasons for any conflicting results.

-nfer 4hy do you think it was important to stir the li#uid in the cupsas the ice melted?

Su22ari:e :escribe what you learned about the rate that ice melts in

water of different temperatures. )ist anything you still want to know.

,!at ; learned

,!at ; still &ant to kno&

,n&y-e ources o! /rror 4rite a paragraph describing how errors in measurement

could have affected your conclusions in this e(periment. Tell what you would dodifferently if you repeated the procedure. Hint' How well were you a&le to time the

e(act moment that each ice cu&e completely melted)


20/31

48

)#ANG


21/31

Name Date Class

Melting -ceProle2

6o& does t!e tem"erature of an ice cue7s surroundingsaffect t!e rate at &!ic! t!e ice melts:

L1 ;n t!is acti'ity# you &ill e+"lore !o& t!e tem"erature of

li2uid &ater affects !o& 2uickly ice melts. First# you &illmake a "rediction aout t!e results of t!e e+"erimentusing your ackground kno&ledge and e+"erience &it!ice. ;nclude !o& long you t!ink it &ill take eac! ice cueto com"letely melt into &ater.

( No& design an e+"eriment to test your "rediction. 0set!e noteook on t!e ne+t "age to &rite t!e "rocedureyou &ill follo&. T!ink aout t!e follo&ing 2uestions&!en designing your e+"eriment.

3 0se t!e s"ace on t!e ne+t "age to create a data tale

to record your oser'ations and measurements. Be sureto use t!e correct metric units in your data tale.

Tell your teac!er your !y"ot!esis and descrie your "rocedure efore testing it. Once your "rocedure isa""ro'ed# run your e+"eriment and record your resultsin t!e data tale.

4*

)#ANGC

&esign an


22/31

Name Date Class

La -n'estigation

5+

)#ANG


23/31

Name Date Class

La -n'estigation

Anal$:e and )onclude

Predict 4as your not. prediction supported by the results of the e(peri-

ment?


24/31

Name Date Class

La -n'estigation

Melting -ce

Anal$:e Sources of


25/31

52

)#ANG


26/31

Name Date Class

/ee*ing )ool4hen a li#uid evaporates+ it absorbs energy from its surroundings so that

the molecules of the li#uid can escape into the air. In this activity+ you will

measure the temperature change that occurs when two li#uids evaporate.

-N;-4+ 0);S -nter*ret &ata

Procedure

1 ,ra" t!e uls of t&o alco!olt!ermometers &it! e2ual amounts of gaue.

( Place a "encil on t!e "a"er to&el# t!en lay t!et!ermometers across t!e "encil so t!at t!e ulends are raised.

3 0se a dro""er to "ut $= dro"s of &ater on t!egaue surrounding t!e ul of one t!ermometer.

Put $= dro"s of ruing alco!ol on t!e gauesurrounding t!e ul of t!e second t!ermometer.

. *ead and record t!e tem"eratures on t!e t&ot!ermometers e'ery minute for fi'e minutes.

Thin" -t 0'er

)ook at your data. 4hich li#uid evaporates faster? &ow do you know?

4hy do you think nurses used to use rubbing alcohol on a patient who had a

fever?

53

)#ANG


27/31

Name Date Class

0ser'ing Suli2ation%ome solids can sublime+ or skip the li#uid state and go directly to the gas

state. :ry ice+ or solid carbon dio(ide+ can sublime at room temperature.

-N;-4+ 0);S -nfer

Procedure

1 Pour $8= millimeters of &ater into a)8=%mL Erlenmeyer flask. Place a t!ermometer int!e flask. )A;T-0NE Wipe up any spilled water right away to avoid slips and falls.

( Oser'e &!at !a""ens after your teac!er adds a small"iece of dry ice to t!e flask. )A;T-0NE Dry ice can

damage skin on contact. Do not touch the dry ice.

3 *ecord t!e tem"erature of t!e &ater (ust after t!e dryice is added and again after it is no longer 'isile.

Thin" -t 0'er

4hat happened when the dry ice was added to the water?

:id adding the dry ice cause the water to boil?


28/31

Name Date Class

#o% )an Air /ee* )hal"ro2 rea"ing?Bubble wrap is a sheet of plastic with air bubbles trapped in it. In this activityyou will test how well bubble wrap prevents an ob3ect from breaking. Then

you will use previous knowledge to e(plain how bubble wrap works.

-N;-4+ 0);S -nfer

Procedure

1 Set aside one "iece of c!alk. ,ra" a second "iece of c!alk in "lastic food &ra" or &a+ "a"er. Secure &it!ta"e. ,ra" a t!ird "iece of c!alk in "lastic ule

&ra". Secure &it! ta"e.( Stand on a c!air. Dro" t!e un&ra""ed "iece

of c!alk on a !ard floor. Oser'e &!at !a""ensto t!e c!alk.

3 Dro" t!e "iece of c!alk &ra""ed in "lastic &ra" or &a+ "a"er from t!e same !eig!t as used in Ste" $.Oser'e t!e results.

Dro" t!e "iece of c!alk &ra""ed in ule &ra" fromt!e same !eig!t as used in Ste" $. Oser'e t!e results.

Thin" -t 0'er 2ompare the results from %teps + 9+ and J.

4hat properties of the bubble wrap accounted for the results in %tep J?

55

GAS


29/31

Name Date Class

#o% Are Pressure andTe2*erature 4elated?4hen a gas is heated+ the particles move faster and collide more often withthe walls of their container. This causes increased pressure within a closed

container. In this lab+ you will observe how a gas8s temperature affects its

pressure.

-N;-4+ 0);S -nfer

Procedure

1 Put t!e ca" on t!e ottle ut do not tig!ten. S2ueeet!e ottle to make sure air can enter and lea'e.

( Place t!e ottle in t!e ice at! and let it cool for

$= minutes. Do not allo& &ater to enter t!e ottle.

3 Tig!ten t!e ca" to seal t!e ottle efore remo'ing itfrom t!e ice at!. S2ueee t!e ottle and note t!eamount of force it takes.

*emo'e t!e ottle from t!e ice at! and "lace it int!e !ot &ater at! for $= minutes. ou mig!t &ant to kee"your !and on t!e ottle to kee" it in t!e &ater.

. Again# s2ueee t!e ottle and note t!e amount of force it takes.

5 Loosen t!e ca" slig!tly and note &!at !a""ens.

Thin" -t 0'er &ow did the air temperature in the bottle change when you put it in hot water?

4hat happened to the air pressure in the bottle when you put it in hot water?&ow do you know?


30/31

Name Date Class

#ot and )old alloonss the temperature of a gas increases+ so does the gas8s volume. This is

because the particles move faster and spread out. In this lab+ you will

observe what happens when a gas is heated.

-N;-4+ 0);S 0ser'e

Procedure

1 Put on your safety goggles and a"ron. Blo&u" t&o alloons so t!ey are e+actly t!e same sie.9not t!e ends so air does not esca"e. Do not inflatet!e alloons too muc!.

( Place one of t!e alloons in t!e tu of ice &ater

and t!e ot!er alloon in t!e tu of &arm &ater. 0set!e rulers to "us! do&n on t!e alloons so t!ey aremostly under&ater. 6old t!e alloons under&ater for t&o minutes.

3 uickly remo'e t!e t&o alloons from t!e &ater and com"are t!eir sies.

Allo& t!e alloons to sit on t!e tale for $= minutes and com"are t!e sies again.

Thin" -t 0'er

:escribe the si"es of the balloons the moment you removed them from the water.

&ow did the si"es of the balloons change as they sat on the table for 1 minutes?

$se your knowledge of molecular motion to e(plain what you observed.

57

GAS


31/31

Name Date Class

-t7s a Gas>There is a definite relationship between the volume of a gas and the

pressure applied to it. In this activity+ you will change the pressure

applied to a gas and note how the gas8s volume changes.

-N;-4+ 0);S &ra% )onclusions

Procedure

1 Pull ack t!e "lunger of t!e syringe as far as it &ill go&it!out going "ast t!e markings. 0se a small allof clay to seal t!e small o"ening of t!e syringe.Be sure t!e seal is airtig!t.

( 6old t!e syringe u"rig!t &it! t!e sealed end on

a tale. 6a'e your "artner "lace one ook on t!e"lunger of t!e syringe. Steady t!e ook so t!at itdoes not fall.

3 Note t!e 'olume s!o&n y t!e "lunger. Add a secondook# t!en a t!ird# and note t!e 'olume eac! time.

*emo'e t!e ooks one at a time and note t!e 'olumeafter eac! ook is remo'ed.

Thin" -t 0'er

4hat happened to the gas volume when you added books 0increased pressure?

4hat happened to the gas volume when you removed books 0decreased pressure?

&ow would you describe the relationship between the volume of a gas and the

pressure applied to it?

Materials

sturdy "lastic syringe#58%cc or =%cc ca"acity

modeling clay

5 ooks of identical

&eig!t

teacher lab chapter 2

Documents