Making Your Own Snowflake in a Jar
Summary
In this hands on Chemistry activity, students will see how Borax is dissolved in water to make a solution. They will then see how a supersaturated solution is made by adding more Borax until it will not dissolve any more. Students will observe the beginning formation of crystals as the solution cools. By the next day the students will see the formation of a snowflake made by the crystals. They will discover what a solution is, what a supersaturated solution is, and also observe a physical change. Discussion about liquids and solids will also be taught and observed. They can also make predictions about what might happen if we used sugar or salt.
CollapseLearning Goals
Students will use observation, inquiry, and prediction.
Vocabulary:
-Solid
-Liquid
-Gas
-Solution
-Supersaturated
-Physical change
Discussion about equipment and safety will also be a goal.
Vocabulary:
-Solid
-Liquid
-Gas
-Solution
-Supersaturated
-Physical change
Discussion about equipment and safety will also be a goal.
Context for Use
This activity can be done at most grade levels. It could be adapted for both upper and lower elementary grades. It is a lab and would need a hot plate to boil water or an electric tea pot. Because of safety the teacher would do this as a demonstration in the lower grades. It take two day to complete the crystals. The actual demonstration only takes about 30 minutes. More time will be needed for discussion and the lesson. This a great lesson to do in the winter when students can observe snowflakes.
Description and Teaching Materials
This activity could be introduced with the book "Snowflake Bently" or also by going to the web site www.snowflakebently.com and viewing snowflakes on the projection machine using your computer. It is a perfect time to do this lesson in the winter when you can observe snowflakes outside. Tell the students that they are going to make their own snowflakes in a jar.
Materials:
-Borax (you can buy this in the grocery store by the laundry detergents, it is called 20 Mule Team Borax)
-Pipe Cleaners (one long one for each child cut in thirds)
-String cut in about 2 foot lengths and one pencil for each student
-Something to boil water (adult will do this part)
-Pint jar or large empty yogurt containers
-1 cup measure, tablespoon, spoon to stir
Procedure:
Step 1. Cut the pipe cleaners into 3 parts
Step 2. Twist in the middle to make a six pointed snowflake
Step 3. Optional add string around the edges making the snowflake more interesting. Tie the string to one edge of the 6 sides twist around once then stretch the string to the next edge twist and continue until you are back to where you started make a know. When you are done it will look like a bike tire with spokes. Now tie the other end of the string to a pencil. This will be placed on the edge of the jar with the snowflake hanging in the jar, but first you must make the supersaturated solution. Second grade students can make their own pipe cleaner snowflake and tie the string on by themselves.
Step 4. Boil two cups of water, pour the water into the pint jar. Add one tablespoon of borax at a time-stir. The borax has dissolved. You have made a solution. Continue adding 1 tablespoon at a time until you have added 6 tablespoons (the rate is 3 Tbls per 1 cup of water). Now no more borax will dissolve, some borax may settle to the bottom. Now you have created a super saturated solution.
Step 5. Rest the pencil across the jar so the snowflake hangs into the solution. The crystals will start to form as the solution cools. Leave over night.
Step 6. In the morning remove the snowflake from the jar. Let it dry. It will sparkle with beautiful crystals.
Discuss with the students what has happened. Talk about how it is a physical change. Explain that the hot water helped dissolve the borax, forming a supersaturated solution. When the water cooled, the borax came out of the solution and began to crystallize around the pipe cleaner.
Ask questions and leave room for inquiry. What would happen if we used cool or cold water? How would it work if we used less borax? Would it work with salt or sugar?
Give the students time to write in their journals what they observed. I follow up this activity with a unit on states of matter. They have now seen how solid and liquids change and it is just a fun way for them to see chemistry.
Materials:
-Borax (you can buy this in the grocery store by the laundry detergents, it is called 20 Mule Team Borax)
-Pipe Cleaners (one long one for each child cut in thirds)
-String cut in about 2 foot lengths and one pencil for each student
-Something to boil water (adult will do this part)
-Pint jar or large empty yogurt containers
-1 cup measure, tablespoon, spoon to stir
Procedure:
Step 1. Cut the pipe cleaners into 3 parts
Step 2. Twist in the middle to make a six pointed snowflake
Step 3. Optional add string around the edges making the snowflake more interesting. Tie the string to one edge of the 6 sides twist around once then stretch the string to the next edge twist and continue until you are back to where you started make a know. When you are done it will look like a bike tire with spokes. Now tie the other end of the string to a pencil. This will be placed on the edge of the jar with the snowflake hanging in the jar, but first you must make the supersaturated solution. Second grade students can make their own pipe cleaner snowflake and tie the string on by themselves.
Step 4. Boil two cups of water, pour the water into the pint jar. Add one tablespoon of borax at a time-stir. The borax has dissolved. You have made a solution. Continue adding 1 tablespoon at a time until you have added 6 tablespoons (the rate is 3 Tbls per 1 cup of water). Now no more borax will dissolve, some borax may settle to the bottom. Now you have created a super saturated solution.
Step 5. Rest the pencil across the jar so the snowflake hangs into the solution. The crystals will start to form as the solution cools. Leave over night.
Step 6. In the morning remove the snowflake from the jar. Let it dry. It will sparkle with beautiful crystals.
Discuss with the students what has happened. Talk about how it is a physical change. Explain that the hot water helped dissolve the borax, forming a supersaturated solution. When the water cooled, the borax came out of the solution and began to crystallize around the pipe cleaner.
Ask questions and leave room for inquiry. What would happen if we used cool or cold water? How would it work if we used less borax? Would it work with salt or sugar?
Give the students time to write in their journals what they observed. I follow up this activity with a unit on states of matter. They have now seen how solid and liquids change and it is just a fun way for them to see chemistry.
Teaching Notes and Tips
Make sure you talk to the students about safety.
-Boiling water can burn
-You should not eat or taste Borax
-Don't move the pipe cleaner once it has been placed into the jar, let it sit overnight. T
he snowflakes will last for years. Over time the crystals will turn solid white and not crystal clear, but this takes at least a year or longer.
-Boiling water can burn
-You should not eat or taste Borax
-Don't move the pipe cleaner once it has been placed into the jar, let it sit overnight. T
he snowflakes will last for years. Over time the crystals will turn solid white and not crystal clear, but this takes at least a year or longer.
Assessment
To assess this activity, I would look at the crystals that the student made to see if they had followed the directions. I would also read what they had written in their notebooks about observation and prediction. We would also have following lessons on states of matter that would have a written assessment to check students understanding of solid, liquid, and gas.
Standards
Grade 2 II. Physical Science A. Structure of Matter The student will understand that objects can be sorted and classified based on their properties.
Benchmark 2. The student will classify a substance as a solid, liquid or gas.
3. The student will know that solids have a definite shape and that liquids take the shape of their container.
4. The student will observe that water can be a solid or liquid and can change from one state to the other.
Benchmark 2. The student will classify a substance as a solid, liquid or gas.
3. The student will know that solids have a definite shape and that liquids take the shape of their container.
4. The student will observe that water can be a solid or liquid and can change from one state to the other.