A Human
Snowflake
The Snowflake after it has melted
11.
A.
To
teach about the water cycle, let each child pretend to be a water
molecule. Tell them that they are floating high in the sky in a cloud.
As the temperature gets colder they begin to stick together and form a
snowflake. Snowflakes are always six-sided due to the shape of the
water molecule (H20). Have 6 students form a hexagon by grasping each
other's shoulders. Six more students will grasp the elbows of two
people in the hexagon with one hand and extending the other straight
out. As the snowflake drifts through the cloud it picks up six or
twelve more people (depending on the size of the class). Have these new
students
grasp the extended hands, adding to the snowflake. Have the "snowflake"
rock back and forth gently as if it is falling from the cloud. Finally
it falls to the ground (still intact). The teacher or another student
can hold up a circle of yellow paper simulating the sun. Tell the
students that the temperature has risen above 32 degrees F or 0 degrees
C. Ask them what would happen at that temperature. Have the snowflake
begin to fall apart as it melts (students drop hands and lay on the
floor). As the sun rises in the sky the "water molecules" begin to rise
from the floor and jump into the air to start the cycle all over again.
(Discuss evaporation, condensation, and precipitation)
B.
How
to
make a Paper Snowflake
Math, science,
art, writing, geography
Math:
This
project could be used as a math activity to reinforce teaching
fractions,
adding or multiplying by 3’s and cutting shapes.
Science:
Snowflakes
are always 6-pointed due to the shape of the water molecule (H20). Draw
a water
molecule on the board.
When the water molecules freeze high in the clouds, they join together
in a 6-sided
form (hexagon), with the hydrogen atom of one molecule touching the
oxygen atom
of the next molecule and so on.
As this
“central core” falls through
the
clouds, it begins to pick up more and more molecules, soon a snowflake
forms.
Since snowflakes always have 6 sides, you must start out with a circle,
if you use
a square, you’ll have 4-sided snowflakes (which is physically
impossible and
scientifically incorrect)!
Supplies: Paper, a
protractor or something round to trace around (depending on the age and
ability
of the students), scissors, paper punch and serrated craft scissors (if
desired)
- Draw or trace a circle of the desired size
on a piece of paper and cut out circle.
- Fold
the circle in half.
- Then
fold it into equal thirds.
- Cut
designs through all thicknesses at the top, the folds, and even the
center point. It is important that the students don’t cut too much on a
fold, the snowflake may fall apart! Hole
punches make nice, clean circles. Serrated craft scissors make
interesting outer edges. Older students may enjoy cutting hearts,
stars, ovals and other shapes in the snowflake.
- Open
out the snowflake when finished, put on the classroom windows or the
door for everyone to enjoy!
- Writing:
Students
could make up a story about their snowflake to tell about where it
began and where it ended up.
- Geography:
Find out about your local
weather patterns to learn where your rain and snow clouds originate.
This is a good time to discuss the water cycle and make the “Human
Snowflake” (Activity #11A).
12.
Geology (for grades K
– 8)
Some
of these sections will have more than your grade level
may need to know, you can modify the information to fit your curriculum
and the
students’ level of understanding. Use the website to show photos of
rocks in their natural environment by typing keywords into the second
search box.
Look on the Geology
and Topography of Tennessee gallery to see photos of the different
kinds of rock in their natural environment.
Begin
the class talking about the layers of the earth (inner core, outer
core, mantle, crust) and how minerals are formed deep
below the Earth’s crust in the mantle layer (magma). The hot magma is
like a
giant stewpot and the minerals are the “ingredients” that make up the
“rock
stew”. Heat from the core (from radioactive decay) is the “fire” that
warms the pot. Explain
that rocks
are made up of 2 or more minerals. Show a piece of granite, the
large crystals of quartz, feldspar and hornblende are easy to see.
Quartz Crystals
There
are 3 basic
types of rocks:
1.
Igneous rocks (basalt, granite,
lava, obsidian, pumice)
were the first rocks on earth. Igneous
means “from fire”. Talk about
how they
would have formed. Was it a long time ago (millions or billions of
years ago
if they cooled beneath the surface) or recently (in volcanic
eruptions)? Did
they form deep underground and become exposed by erosion, or did they
form
above the earth’s surface? Igneous rock that formed and cooled slowly
underground is called intrusive; if it formed above ground,
from a
volcano, it is extrusive. Which ones formed slowly (granite)?
Rocks that
cooled slowly (thousands to millions of years) have larger crystals;
rocks that
cooled quickly have small crystals. Which ones formed rapidly (basalt,
pumice,
scoria, “lava”, obsidian)? Discuss ways igneous rock can be worn down
and
eroded (rain, wind, ice expanding in cracks, acids from lichens). What
happens
to the eroded rock?
Show photos of igneous rock from the EastTennesseeWildflowers website
by typing
“igneous” into the second search box. Discuss how people have used
igneous
rocks (obsidian stone knives, jewelry, building stones, statues,
cemetery
headstones, flooring, gravel, “grit” in cleaning agents, pumice stones
for
rough skin, tourist attractions such as the volcanoes in Hawaii, Mt.
Rainier,
Lassen Volcano NP, Yosemite NP, Acadia NP, Mt. Rushmore)
2.
Discuss Sedimentary rocks (sandstone,
limestone,
conglomerate, shale, chert, coal) and how they formed. About 75% of the
earth’s
surface is
covered with sedimentary rock.
A.The first sedimentary rocks would
have formed from broken down igneous rock. If available, look at grains
of beach sand through a dissecting microscope or with a strong
magnifying glass, note the different colors of the sand grains. (Note:
some areas, such as the Gulf Coast of Florida, have mainly one type of
rock in the sand, resulting in the pure white sand.) It is interesting
to collect sand from different areas of the country while traveling.
When small pieces of eroded rock (sand, pebbles, silt) are compacted,
cemented, and recrystallized, they become “lithified” (turned to
stone); they can become shale, sandstone, conglomerate, or breccia,
depending on the size and shape of the rocks. Make a sediment jar (see
activity #12) to let the students observe the sizes of the rocks in the
layers. The famous Red Rock of southern Utah is a beautiful example of
sandstone. Arches, Canyonlands, and Capitol Reef National Parks
showcase the awesome power of time, wind, and water in the arches, deep
canyons, hoodoos, and multicolored layers in the rock.
B. Limestone and
dolostone are
considered “carbonates”, they were formed through both biochemical and
chemical processes. Limestone contains calcite (CaCO3), which
was derived from the shells of ancient sea creatures that died and
settled on the seafloor hundreds of millions of years ago. Over
millions of years, the shells were compacted, chemically cemented
together, and then recrystallized into limestone. It is common to find
fossils in some kinds of limestone. A fun test to do on “fossiliferous”
limestone is to put a couple of drops of hydrochloric acid on it; if
the rock bubbles, it is limestone. The alkaline calcium carbonate
reacts with the acid and releases carbon dioxide gas bubbles. Chalk is
another type of limestone that was formed from the shells of
microscopic aquatic organisms. The White Cliffs of Dover, England are a
good example of chalk. A walk along a beach
in Florida or
Barbados may reveal another type of limestone called “coquina”, it is a
mixture of seashells, sand, and pebbles cemented together with calcite.
Coquina Rock
- Show
photos of sedimentary rock
from the EastTennesseeWildflowers website by typing “sedimentary” into
the
second search box.
- Talk
about how people have used
sedimentary rock (building material “flagstone”, cement, gravel,
tourist
attractions such as the Grand Canyon; Arches, Canyonlands, and
Capitol Reef National
Parks)
3.
Discuss tectonic plates, fault
zones, earthquakes, ocean trenches, and volcanoes and how the earth is
constantly moving beneath the crust. Explain that the heat from the
earth’s
core acts like a stove eye and the magma in the mantle acts like water
boiling
in a pot. The magma near the core is hotter (around 4000 degrees F) and
slowly
rises, while the magma near the crust is cooler (around 1500 degrees F)
and
sinks. The movement and pressure of the magma puts stress on some areas
of the
crust causing it to pull apart, push together, or slide, these are
called
“faults”. Show the earthquake website: http://www.iris.edu/seismon/
to illustrate the most active areas on earth. The areas with the most
purple
dots on the map are where the faults are located. In some areas of the
earth,
the lighter oceanic crust is forced under the heavier continental
crust. It is
in these areas that oceanic trenches occur, volcanic and earthquake
activity is
high in these areas. Rock is melted and “recycled” in the subduction
zones
beneath the trenches, volcanoes often form near trenches. If possible,
show the
class a raised relief map of the west coast states and note the chain
of
volcanoes. Discuss the San Andreas fault in California and the “Ring of
Fire”
along the Pacific Coast.
Ok, now to the metamorphic rock!
It is important for
students to understand what goes on beneath the earth’s surface before
they can
understand how metamorphic rocks form. There are 3 ways that
metamorphic rocks
occur:
- Heat - When rocks are
exposed to a tremendous amount of heat and pressure beneath the
surface, they buckle, bend and often melt. This changes the crystalline
structure of the rock to make it become a new type of rock. When rock,
such as granite, is compacted it pushes the minerals closer together
making the new rock more dense and it often becomes striated (striped)
or layered. Granite becomes “gneiss” (pronounced – “nice”), which has
very prominent stripes. Lava and magma coming in contact with rocks can
cause them to change too.
- Pressure – Rocks that are
subjected to tremendous amounts of pressure, due to either burial under
heavier rock or tectonic pressure can metamorphose. This can happen
from 3 to nearly 25 miles beneath the surface of the earth.
- Chemical fluids – When
water is exposed to magma close to the surface, minerals are released
into the seawater and settle out on the seafloor. “Black smokers” in
the vent zones of the ocean floor belch out massive amounts of
minerals. Ore deposits in mountain ranges formed in a similar way when
water seeped through cracks in the rocks long ago.
Some metamorphic rocks include:
Gneiss from granite (parent rock)
Marble from limestone
Schist from basalt
Slate from shale
Quartzite from quartz sandstone
Metagraywacke from greywacke
Serpentinite from peridotite
Soapstone (steatite)
from peridotite
Metamorphic
minerals
include:
Garnet
Talc
Graphite
Tourmaline
Asbestos
Show photos of metamorphic rock from the
EastTennesseeWildflowers website by typing “metamorphic” into the
second search
box above.
Discuss
how people use metamorphic rock (eyeshadow, building
materials, carving rock [soapstone], cemetery, gemstones, jewelry,
headstones,
pencil lead, fire retardant)
The Rock Cycle
Draw
this diagram on the board. Write the names of the
three types of rocks at each point of the triangle. Explain that over
enough time (hundreds to billions of years), all
rocks
can change from one form into another.
Igneous
rock is broken down into sediments, which
eventually become sedimentary rock; it can also be transformed into
metamorphic
rock by heat and pressure; or it can be re-melted back into the magma.
Sedimentary
rock can be re-melted back into the magma
to become igneous rock once again; it can also be transformed into
metamorphic
rock by heat and pressure; or it can be broken down into sediments,
which
eventually become sedimentary rock again.
Metamorphic
rock can be broken down into sediments,
which eventually become sedimentary rock; or it can be re-melted back
into the
magma.
To help the younger students get a better grasp of
this,
give them 3 different colors of modeling clay, Play-doh(TM), or
home-made
“salt and
flour clay”. Start out with a few large chunks (quarter-sized) of clay,
these
will be the igneous rocks. Have the students break some off into
several
pea-sized
pieces, this is sand or sediment. Gently press the “sand grains”
together so
that they are attached, but not smashed together, this is sedimentary
rock. To
make metamorphic rock, let the students press and bend the sandstone to
make
twisted layers.
Igneous
rocks
|
Sedimentary
rock
|
Metamorphic
rock
|
Helpful geology links:
http://www.gpc.edu/~pgore/geology/geo101/sedrx.htm
http://www.geo.ua.edu/intro03/Seds.html
Volcano and
earthquake links:
http://volcano.und.nodak.edu/
http://www.iris.edu/seismon -
for daily global earthquake activity
Sedimentation jar
To teach about the formation of sedimentary rocks, have students
bring in a clear 16 ounce plastic water bottle. Add about an inch
(each) of soil, sand, and small rocks to the bottle and fill with
water. Replace the lid and add duct tape around the lid to avoid leaks
or "accidents". Shake the bottle and listen to the rocks and sand as
they hit the side. Have the students listen as they stop shaking the
bottle. Ask what they hear (they should tell you that they hear the
rocks hitting the bottom and then the sand). Ask what they think is
happening to the contents of the bottle. The rocks settle first since
they are the largest, next the sand settles, and the mud will take some
time to settle. Set the jars aside and look at them 15 - 30 minutes
later. Ask the students what they see.
Draw a sediment jar on the board
with the rocks at the bottom, the sand, and then the mud and water
layers (I like to use different colors for each layer). Label each
layer on the right side of the drawing. Discuss that this is what
happened to pebbles, sand and mud long ago along river banks, beaches,
and on the sea floor. On the opposite side of the drawing write
"conglomerate" next to the rock layer, "sandstone" next to the sand
layer, and "shale" next to the mud layer. Explain that over a very long
period of time the different layers turned to the different types of
stone. Discussion of fossils could be added to the lesson since they
are formed in sedimentary rock.
Science Outreach Programs
(for schools in the East Tennessee area)
I have been involved
in teaching science outreach programs in the east Tennessee area since
1987. The Ecological and Physical Sciences Study Center began in 1986
through the Oak Ridge National Laboratory. In April 2006 the program
was transferred to the American Museum of Science and Energy in Oak
Ridge. The classes are taught at the schools, at the museum classroom
or at our outdoor facility in the 19th-century cabin at Freels Bend on
Melton Hill Lake. During the 1 - 2 hour classes, the
students enjoy learning about science through hands-on activities. We
presently have 4 instructors, I teach the natural sciences along with a
few of the physical sciences. I am available to teach on Thursdays and
Fridays. For more information see the AMSE Outreach link.
