Name______period______
Crystal Snowflake Ornament
How do snowflakes form? What kind of weather conditions make snow? What are crystals and how do they form?
A snowflake begins to form when an extremely cold water droplet freezes onto a pollen or dust particle in the sky. This creates an ice crystal. As the ice crystal falls to the ground, water vapor freezes onto the primary crystal, building new crystals – the six arms of the snowflake.Theice crystals that make up snowflakes are symmetrical (or patterned) because they reflect the internal order of the crystal’s water molecules as they arrange themselves in predetermined spaces (known as “crystallization”) to form a six-sided snowflake.
Ultimately, it is the temperature at which a crystal forms — and to a lesser extent the humidity of the air — that determines the basic shape of the ice crystal. Thus, we see long needle-like crystals at 23 degrees F and very flat plate-like crystals at 5 degrees F.
The intricate shape of a single arm of the snowflake is determined by the atmospheric conditions experienced by entire ice crystal as it falls. A crystal might begin to grow arms in one manner, and then minutes or even seconds later, slight changes in the surrounding temperature or humidity causes the crystal to grow in another way. Although the six-sided shape is always maintained, the ice crystal (and its six arms) may branch off in new directions. Because each arm experiences the same atmospheric conditions, the arms look identical.
So, why are no two snowflakes exactly alike?Well, that’s becauseindividual snowflakesall follow slightly different paths from the sky to the ground —and thus encounter slightly different atmospheric conditions along the way. Therefore, they all tend to look unique, resembling everything from prisms and needles to the familiar lacy pattern.
How does borax form crystals?Borax is an example of crystal- “a solid with flat sides and a symmetrical shape because its molecules are arranged in a unique, repeating pattern.” Every crystal has a repeating pattern based on its unique shape. They may be big or little, but they all have the same “shape”. Salt, sugar, and Epsom salts are all examples of crystals. Salt crystals are always cube-shaped while snow crystals form a six sided structure.Hot water holds more borax crystals than cold water. That’s because heated water molecules move farther apart, making room for more of the borax crystals to dissolve. When no more of the solution can be dissolved, you have reached saturation. As this solution cools, the water molecules move closer together again. Now there’s less room for the solution to hold onto as much of the dissolved borax. Crystals begin to form and build on one another as the water lets go of the excess and evaporates. This also applies to snowflakes - As water cools the molecules move closer together. Since all water molecules are shaped the same, they align in a six sided crystal.
Procedure:
1. Form a snowflake out of a white pipe cleaner.
2. Measure the length of the string needed to suspend it into a cup, without it touching the bottom.
3. Tie the string onto a craft stick so that it can be suspended in the solution overnight.
4. Have your teacher pour boiling water into a cup for you. Be careful not to burn yourself or others!
5. Stir in ______grams of borax powder. Wear goggles and don’t get it into your eyes!
6. When the powder is dissolved, place the pipe cleaner into the solution.
7. Leave it still and to sit overnight.
Answer the following questions. You may research the information on a computer or on your phones.
1. When you dissolve the powder in the hot water, is that a chemical or physical change? ______
2. How do you know? Support your answer with evidence. ______
______
3. Why is it important for you to keep the solution and pipe cleaner still? ______
______
4. What other type of powder do you think you could use to make crystals? ______
______
5. How is the process of making borax crystals similar to how a real snowflake forms? ______
______
6. How could you modify these snowflakes to make them a different way?______
______
7. Which has more energy in its molecules, hot water or cold water? ______
8. What happens to the energy of the water and borax molecules as the water cools?______
______
9. If the water cooled too quickly, or even froze solid, what would happen to the borax crystals? ______
______
10. Based upon the chemical structure of a snowflake, do they always have 6 sides? ______
11. Why? ______