Creating a borax snowflake combines chemistry and creativity. This experiment demonstrates the concept of super saturation but also mimics how real snowflakes form in the cold by crystallizing on a nucleus.
Snowflakes begin as tiny water droplets suspended in clouds. When the temperature in the clouds drops below freezing (32°F or 0°C), these droplets can freeze into ice crystals. However, for this to happen, the water vapor often needs a nucleus—a particle like dust, pollen, or salt—to cling to as it freezes. Once the initial ice crystal forms, more water vapor in the cloud condenses onto its surface. This is where the magic begins. Water molecules arrange themselves into a hexagonal lattice because of the way hydrogen bonds form between molecules in ice. This six-sided symmetry is the foundation of all snowflakes.
As the crystal grows, it branches out in intricate patterns. Each branch is influenced by temperature, humidity, and the surrounding environment. Because the same conditions affect all parts of the snowflake simultaneously, the six arms of the snowflake usually grow in symmetrical patterns.
However, no two snowflakes are exactly alike. Tiny variations in the atmosphere, like changes in temperature or humidity, create unique patterns on each crystal. Despite this uniqueness, all snowflakes share the hexagonal symmetry due to their molecular structure.
Not all snowflakes are the classic "stellar dendrites" (the intricate, feathery ones). They can also form as:
- Plates: Thin and flat, often hexagonal.
- Columns: Long, slender, and tube-like.
- Needles: Thin and elongated.
- Capped Columns: A combination of plates and columns.
We will be creating our snowflakes with borax, not water vapor. This is done using a concept called supersaturation. When borax powder (sodium borate) is added to hot water, it dissolves, breaking down into individual ions. Hot water can hold more dissolved borax than cold water because higher temperatures increase the solubility of the substance by increasing the space in between the water molecules. This creates a supersaturated solution—a liquid holding more solute than it normally would at room temperature. As the solution cools, its ability to hold borax decreases. The dissolved borax begins to separate out of the water. This process is driven by the fact that cooler water cannot maintain the same level of saturation as hot water.
For the borax to start forming crystals, it needs a surface to latch onto. This surface can be any solid material, such as pipe cleaners, string, or the walls of the container. These are called nucleation sites, where the borax molecules gather and start to bond. As more borax comes out of the solution, the molecules continue to attach to the growing crystal lattice at the nucleation sites. The molecules arrange themselves in a specific pattern due to the chemical properties of borax, forming a repeating structure that grows into a larger crystal. The process continues until the solution reaches equilibrium, all the dissolved borax has been crystallized, or the experiment is stopped.
The size and clarity of the borax crystals depend on factors like:
- Time: Longer cooling times allow larger, more well-defined crystals to form.
- Concentration: A highly concentrated solution can produce more rapid but smaller crystal growth.
- Temperature: Higher initial temperatures can help dissolve more borax, leading to larger crystals as the solution cools.
Borax molecules naturally form a monoclinic crystal system, resulting in flat surfaces that reflect light, giving the crystals their glittery, jewel-like appearance.
You can easily try this experiment at home! Watch our video below to see just how easy it is!
What You’ll Need:
- 1.5 Cups Borax Powder
- 4 Cups hot water
- Pot
- Spoon
- Jar or cup
- Pipe cleaners
- (stove or hot plate)
Instructions:
- Measure the borax and water into a pot.
- Boil the borax solution until the powder complete dissolves.
- Allow the solution to cool slightly. In the meantime, shape a pipe cleaner into the shape you want your crystals to form (such as a snowflake). Use a few pieces to form the classic six-sided design.
- Fill a jar or cup with the warm borax solution.
- Wrap the pipe-cleaner around the spoon (or tie a string from the pipe-cleaner to the spoon) and submerge the pipe cleaner in the solution so that it is hanging from the spoon. DO NOT touch the bottom or sides of the container.
Get the full experiment, with scientific method worksheets and 3-2-1 learning questions below:
By experimenting with borax crystallization, you can demonstrate principles like solubility, supersaturation, and the orderly nature of crystal formation—a hands-on way to bring chemistry to life!