TEACHER RESOURCE GUIDEPREFERRED ACTIVITIES

Education Outreach With Generous Support from theMaxwell H. Gluck Foundation

Complete Teacher Guide available at www.nhm.org/outreachAlso available on Skymobile Resources USB

A rock’s a rock, right? Not quite. In this quickand tasty activity students will better understand

the basic differences between igneous,metamorphic and sedimentary rocks using

marshmallows to model geologic processes.

M AT E R I A L SEach student will need three marshmallows and

some napkins or paper towels

A C T I V I T Y T I M E15-20 minutes

N E W W O R D Signeous rock, metamorphic rock, sedimentary rock

P R O C E D U R E1 Modeling Metamorphic Rocks

Ask students to squish one of the marshmallows betweentheir palms (hard!) for 1 minute. Take a look at the result.Has the marshmallow changed? Is it going back to itsoriginal shape? What changed it? (Heat and pressure havechanged this marshmallow, like a metamorphic rock.)

2 Modeling Igneous RocksHave students place a marshmallow in their mouth, butinstruct them not to chew or swallow. After about 1minute, have the students remove what’s left of theirmarshmallow and place it on a napkin or paper towel.Look at the ‘rock’. Is it the same as it was? Whathappened to it? Is it getting harder as it sits on the papertowel and cools off? ( Igneous rocks are formed frommelted rock that has cooled.)

3 Modeling Sedimentary RocksAsk the students to break the last marshmallow up intoat least 5 pieces. Have students put their pieces backtogether again. Is it the same shape or size as it wasbefore it was broken? (Small bits and pieces of rock makeup the whole in sedimentary rocks.)

45

Marshmallow Rocks

When you notice how objects are similar, you’rethinking like a scientist. Scientists classify things

into groups by looking at how they are alike ordifferent. For example, one way that geologistsclassify rocks is by the size of the particles that

they’re composed of. Scientists can observe theparticles of one rock and compare them to the size

of other rocks’ particles. This method allowsscientists to classify and identify rocks with

similar-sized particles.

In this activity, students develop a simple classification scheme for everyday objects. This is the first activity in a series of three

activities which emphasize the process and purpose of classification.

M AT E R I A L SFor each team: one bag of 12 picture cards (bird,

bicycle, car, butterfly, flower, surfboard, deer, football,airplane, boat, tree, and fish). A class set of picture

cards is available in the Skymobile Teaching Kit.Optional: One student worksheet for each team.

A C T I V I T Y T I M EUp to 30 minutes

N E W W O R D Sclassification, dichotomy

PR O C E D U R E1 Begin by discussing with students different ways of

grouping objects. This may include grouping objects byphysical appearance (color, etc.), purpose or use, behavior,living or non-living, and various other methods. Ask why itis important for scientists to group objects? If time permits,you might do some sample grouping with the students.(Students who are wearing tennis shoes vs. students whoare not, or students with yellow pencils vs. students withother-colored pencils, etc.)

2 Divide the students into groups of 3 or 4 and give eachteam a set of picture cards. Distribute the accompanyingstudent worksheet (one per team).

3 Each team should take the cards out of the bag and surveyall of the objects on the cards. The students should thendiscuss with their team members ways in which the objectscan be grouped by using all 12 cards. Have each group ofstudents sor t the picture cards into groups based onsimilarities or patterns of the objects. There are no right orwrong categories. After five minutes has passed or afterseveral groupings have been determined, each teamshould complete their student worksheet.

4 Once all of the teams have finished the studentworksheet, call upon one team to share their categorieswith the class. Their responses could be recorded on theboard, or their cards could be attached to a large piece ofpaper. Each team should be given a chance to explainand discuss their groupings.

VA R I AT I O N SGuess My RuleOnce the bags of cards are distributed to each team, have onlyone teammate look at the picture cards. He/she shouldcategorize them without sharing his/her ideas with the othermembers of the group. When the student is finished grouping,have the other team members look at and guess ways in whichthe objects were grouped. To help with this process, theteammates can think of an object that is not in the group andask if it belongs. The student can only answer “yes” or “no.”Once the categories have been revealed, switch students andrepeat process.

DichotomiesOnce the bags of cards are distributed to each team, have the team think of only two main categories that all cards must fit into. Can the students sub-group the cards within the two categories using all of the cards? See if they are up for the challenge!

A C T I V I T Y C A R D SThe Skymobile Teacher Kit comes completewith pre-made cards for this activity.However, the copies of the cards have beenincluded in Appendix D for future use

53

Classified

Classified!

when the Teacher Kit may not be available

Scientists use keys to help identify objects. Keys can come in different formats: flow charts, cladograms, and written couplets are just a few.

In this activity, students will classify anassortment of objects (beads) using a flow chart

that is set up using yes-no questions. This issometimes referred to as a dichotomous key.

M AT E R I A L SFor each team: bag of 8 beads and Classification

Chart (on the following page) and studentworksheets. Bead sets and classification charts are

available in the Skymobile Teaching Kit.

A C T I V I T Y T I M E30 minutes

PR O C E D U R E1 Divide the students into teams of 3 or 4. Give each team a

bag of beads and a Classification Chart. Also distribute student worksheets to each student (or team).

2 Each team should begin by choosing only one item from thebag. The team will follow the flow chart beginning at “starthere.” Instruct the students to move through the chart byanswering the yes/no questions. With each answer comes anew pathway. Students should select the appropriatepathway and move to the next rectangle on the chart.

3 Students will continue the path until their object has beenidentified by a box that contains the object’s name. Theyshould place the object on that box and begin classifying anew bead. When all of the beads have been classified, thestudents can use the student worksheet to describe theobjects they have identified. Note that students may find iteasier to use the flowchart by placing the bead on the keyand sliding it down the path to each question.

4 After each team has identified each bead, they can checktheir answers with other groups and/or the answer key.

5 Helpful hint: Remind students NOT to go back to the baguntil they have finished identifying the item they selected.Students sometimes choose the item that they thinkshould go on a space on the chart. While this sometimesresults in the right answer, it defeats the purpose ofunderstanding how a classification key works.

C O N C L U S I O N S Discuss with the class the difficulties that they encounteredin using the key. Why might a key like this be useful? How might a scientist use a key like this to identify livingthings or rocks?

55

The Doodad Sort

Answer KeyBelow are descriptions of the beads thatcorrespond to the “names” on the Doodad Sortstudent worksheet

Doodad an animal or plant-shaped wood bead(eg. dinosaur, pig, tree)

Wam a square-shaped wood bead

Widget a tall, round wood bead

Zam a shorter, round wood bead

Gob a thin, triangle-shaped plastic bead

Tong a thin, square-shaped plastic bead

Bop a thin, star-shaped plastic bead

Blub a thin, bow-tie/hourglass-shapedplastic bead

For this activity, students will use a dichotomouskey to identify several rocks and minerals.

Scientists use classification as a way to organizeinformation and help see relationships betweendifferent specimens. Classification schemes are

useful in all branches of science, includinggeology, biology, paleontology and

even chemistry.

M AT E R I A L SFor each team: one set of rock specimens —

these are available in the Skymobile teaching kit. Each student will also need a copy of the

Student Worksheet. (You might choose to have oneworksheet per team.)

A C T I V I T Y T I M E25 minutes

N E W W O R D Sclassification, crystal, dichotomy,

element, mineral

P R O C E D U R E1 Divide the students into groups of 3 or 4. Distribute rock

sets to each team and worksheets to each student.

2 Read the directions together with the students. Remind students that they should choose the statement from thepair that BEST describes the sample they are trying to identify. Once they have decided on a statement, they mustfollow the directions that follow the statement; thesedirections will either tell the team which set of statementsthey should use to continue their questioning, or tell themthe name of their specimen. Remind students that they willnot necessarily use every set of statements for each sample.

3 Once students have completed their identification, askthem to record their results on the data sheet bydescribing the appearance of each specimen. The answerkey can be found in Appendix C.

E X T E N S I O NConsider asking each student to choose one of the rocksamples for further study. This might include recording therock’s appearance by making a sketch or drawing, orgathering more information about that particular rock usingthe library or Internet resources. Possible questions to beanswered by this research include: Where does it comefrom? How is it formed? What is it used for?

Pieces of the Planet

58

PIECES OF THE PLANETS S T U D E N T W O R K S H E E TPA G E 1

For this assignment, you will identify several rock and mineral specimens using a classificationkey. If you can observe each rock carefully and follow the key directions, you’ll soon knowwhich specimen is which!

H O W T O U S E T H I S K E Y

1 Choose one rock specimen to start with.

2 Begin by reading the first set of choices, and discussing them with your team. Decide whichstatement in the pair BEST describes the item you are trying to identify.

3 Follow the directions on the right side of the key. For example, in Choice #6, if you decide that thesample is white, you would continue on to Choice #7; if you decide that the sample is yellow, youwould continue on to Choice #8.

SNOITCERIDSECIOHC

1 Sample is made of different bits and pieces, packed together. Go to choice 2.

eciohc ot oG.tuohguorht epyt eno si elpmaS 4.

2 Sample contains pink, white and black minerals. This is granite .

Sample does not contain pink, white and black minerals. Go to choice 3.

3 Sample has bands of white and black minerals. This is gneiss.

Sample contains tiny bits of seashells. This is limestone .

4 eciohc ot oG.yarg ro kcalb si elpmaS 5.

Sample is not black or gray eciohc ot oG. 6.

5 si sihT.dilos kcalb-ynihs a si elpmaS coal.

si sihT.skaerts der htiw ,revlis-yarg si elpmaS hematite .

6 eciohc ot oG.etihw si elpmaS 7.

Sample is yellow eciohc ot oG . 8.

7 Sample has shiny, clear and white crystals. This is quartz

8 Sample has no crystals, and is solid yellow. This is sulfur .

NAM E

P I E C E S O F T H E P L A N E T S S T U D E N T W O R K S H E E TPA G E 2

Record the results of your classification by describing each of the rocks or minerals listed below.

C O A L

G N E I S S (say “NICE”)

H E M A T I T E

G R A N I T E (say “GRAN-it”)

L I M E S T O N E

S U L F U R

QUARTZ

A P P E N D I X C

A N S W E R K E Y

ETINARGLAOC

G N E I S S

ENOTSEMILETITAMEH

RUFLUSZTRAUQ

Pieces of the Planets

CO A L Coal is the result of layers of ancient organic,decaying vegetation being buried, compactedand heated. It grades from sedimentary to metamorphic qualities by the degree of heating.This sample is Anthracite, the most processedgrade and cleanest-burning variety. Coal is combustible, and is the most abundant fossil fuel.Coal mining began in the Middle Ages andcontinues today.

GR A N I T EGranite is formed from magma (melted rock) thatremained underground and cooled slowly. Over time, uplift and erosion have exposed it. This coarse grained, igneous rock must have these three mineral ingredients to be called granite: quartz (clear or white), mica (black, shiny)and feldspar (pink or white). These minerals arevisible to the naked eye and make granite aneasily identifiable rock.

G N E I S SThis metamorphic rock is the result of high-grademetamorphism. Due to regional heating, the minerals have settled (by density) into distinctblack and white bands.

H E M AT I T EThis mineral ranges in surface color from silver togray-red to red, but always leaves a red streakwhen tested. This mineral may become magneticwhen heated. Hematite is an iron oxide and isessential to the steel manufacturing process.

L I M E S T O N ELimestone is usually of marine origin, formed bycalcium carbonate-rich seashells and corals beingsolidified into rock. It is the result of layers of shelland bone fragments being deposited and compressed by the weight of the ocean water.

Q U A R T Z Quartz is a major ingredient in the Earth’s crust, a large amount being found in most sedimentary,igneous and metamorphic rocks. The Quar tz family of minerals shows great variety, from clearquartz crystal to milky or rose quartz to gem-quality amethyst, jasper and opal. This mineral isheavily used in glass processing and electronics as well.

S U L F U R This mineral is deposited around volcanic ventsand hot springs. Sulfur is a pure solid made of aspecific element, whereas most minerals arecombinations of different elements. It is brightyellow to yellowish brown and has a distinct odor.Sulfur is a common ingredient in fertilizers,plastics and medicines.

A P P E N D I X C

A N S W E R K E Y

Pieces of the Planets

87

AP

PE

ND

IXD

CL

AS

SIF

ICA

TIO

NC

AR

DS

FO

RC

LA

SS

IFIE

D!

AC

TIV

ITY

86

AP

PE

ND

IXD

CL

AS

SIF

ICA

TIO

NC

AR

DS

FO

RC

LA

SS

IFIE

D!

AC

TIV

ITY