1. Topic-
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2. Content-
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creep internal blizzard snow ice |
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3. Goals: Aims/Outcomes-
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1.that they know the terms
2.the learned about snow
3.they gain knowledge |
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4. Objectives-
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TO DAY WE WILL
How can water and ice exist in the atmosphere? How do clouds form
in the atmosphere? How does snow form in the clouds? What conditions
are needed for snow to fall to the ground? What can we say, draw,
write about snow that we look at, touch, and examine in class? |
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5. Materials and Aids-
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The activity enables students to collect evidence that water and
ice is in the atmosphere. For all activities, to record reflections,
observations, calculations, etc. n Science Notebooks: writing and
drawing utensils.
Condensation Demonstration n Ice cubes n See-through drinking glass
or enough clear plastic glasses for everyone n Magnifying lenses or
Proscope n Dry ice
Snow Cycle Model n Aquarium or Terrarium container and cover n A small
handheld battery controlled fan n Shallow container for water n A
sculpted "mountain,"� e.g. oatmeal box with construction paper
n Dry ice* (see safety guidelines Black construction paper n Microscope
or Proscope |
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6. Procedures/Methods-
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A. Introduction-
Seeing is not always believing. It is not obvious that water vapor
is in the air. The appearance of condensation can seem magical to
young children. It may seem mysterious that water droplets appear
on the outside of a glass of ice-cold water. Young students may initially
persist in the belief that that the water has moved through the glass
from inside the glass to the outside. This demonstration aims at inferring
that water vapor is in the air, as a basis for understanding the formation
of snow in the clouds of the atmosphere. |
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Practice-
Up the snow cycle model. Essentially, this is a simple��Ed model
of how snow forms in nature.
Use an aquarium to set up a model of the snow cycle: 1. Place some
water in a shallow container; 2. Place a heat lamp to simulate the
Sun (to accelerate evaporation); 3. Sculpt a "mountain"� (cardboard
box and construction paper) 4. Place some crushed ice over dry ice
on top of the mountain (to simulate a cryospheric location that is
below freezing) 5. Place a two-part glass cover over the environment,
one for the heat lamp side, one for the dry ice side; 6. Place a "cloud,"�
a chunk of dry ice, on top of the glass above the mountain (to assure
sub-freezing atmospheric temperatures for snow formation); 7. Watch
as snow appears on the glass above the top of the mountain; tap lightly
on the glass for the snow to fall.
LESSON 6 DIRECTORY MAIN MENU SNOW IS A FORM OF ICE
PRINT
16
IN THE SOLAR SYSTEM Exploring Ice
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Independent Practice-
WARM-UP AND PRE-ASSESSMENT Share Snow Vivencias* Tell a brief snow
experience story from your own life and/or select a story to read
that has a vivid snow experience as part of the story. Consider telling
the story in such a way that invites students to act it out along
the way. Refer to the story as "a snow experience"� and "an
experience of the phenomenon of snow."�
Invite the students to share a snow experience from their own life
or invent an imaginary snow story. * Vivencia is a wonderful Spanish
word used by poets to describe a vividly remembered experience in
which the details are as fresh and as tangible as the living moments
from which the memories arose. |
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Closure-
PROCEDURES PART 1. Model the Snow Cycle This activity involves observing
that water is in the atmosphere and extending that to understand that
snow forms in clouds. Open a discussion of how snow occurs in the
natural world. Ask guiding questions such as: What happens if water
vapor in the air bumps up against something as cold as ice flfloating
in the air? Let students observe the snow cycle environment, initially
without explanation. Then invite students to ask questions, propose
explanations and discuss what they observe. Let the fan blow on the
water. If managed just right, it accelerates evaporation and produces
a cloud above the dry ice.
n Note: With guidance, mature students can operate the fan. Under
no circumstances should any student be allowed to touch the dry ice
with bare hands. Notice that snow appears on the surface of the dry
ice. It is water vapor freezing directly out of the atmosphere to
the surface of the dry ice. (Actual "snowing"� may or may not
be observable in this simulation.) n This is not to say that there
is dry ice on top of mountains on Earth. The purpose of the dry ice
is to produce the cold temperature in the moist air to produce a cloud
and to produce "snow"� on its surface. n Nevertheless it can
be pointed out that on other planetary surfaces, such as Mars, it
is cold enough for carbon dioxide to form dry ice. Ice caps on Mars
are a mix of water ice (H2O) and dry ice (CO2). In a natural cloud,
when the air cools below freezing, ice crystallizes around dust particles
and then builds up until it is large enough to fall. If the air is
cold enough, it will reach the ground as snow. If it is warmer, it
will melt as it falls and becomes rain. Sometimes it supercools and
builds up rapidly, forming hail. |
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