1. Topic-
2. Content-
creep internal blizzard snow ice
3. Goals: Aims/Outcomes-
1.that they know the terms
2.the learned about snow
3.they gain knowledge
4. Objectives-
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?
5. Materials and Aids-
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
6. Procedures/Methods-

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.


Up the snow cycle model. Essentially, this is a simpleEd 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.

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.


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.

This Lesson Plan is available at (www.teacherjet.com)