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Physics of a snowflake

Snowflakes are formed when water vapor freezes onto a tiny particle in the air, such as a dust grain or pollen. As the ice crystal falls through the clouds, more water vapor freezes onto it, forming branches and other features. The shape of the snowflake is determined by the temperature and humidity of the air through which it falls.

Factors that affect the shape of a snowflake:

• Temperature: At lower temperatures, snowflakes tend to be more complex and have more branches. At higher temperatures, snowflakes are simpler and tend to be more plate-like.
• Humidity: In more humid air, snowflakes tend to have more water vapor molecules freeze onto them, resulting in larger and more complex shapes. In drier air, snowflakes are smaller and simpler.

Common snowflake shapes:

• Dendrites: These are the classic snowflake shape with six branches. Dendrites are formed at low temperatures and high humidity.
• Columns: These snowflakes are long and thin, like columns. Columns are formed at higher temperatures and lower humidity.
• Plates: These snowflakes are flat and plate-like. Plates are formed at the highest temperatures and lowest humidity.

Pictures of snowflakes:

Opens in a new window www.nsf.gov

Opens in a new window fineartamerica.com

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Ten question test:

1. What is the basic shape of a snowflake?
2. What are the three main factors that affect the shape of a snowflake?
3. What type of snowflake is most common at low temperatures and high humidity?
4. What type of snowflake is most common at high temperatures and low humidity?
5. What is the difference between a dendrite and a column snowflake?
6. What is the difference between a plate snowflake and a dendrite snowflake?
7. Why are no two snowflakes exactly alike?
8. How do snowflakes form?
9. What is the temperature range at which snowflakes form?
10. What are some of the different colors that snowflakes can be?

Answers:

1. Hexagon
2. Temperature, humidity, and wind speed
3. Dendrite
4. Plate
5. Dendrite snowflakes have six branches, while column snowflakes are long and thin.
6. Plate snowflakes are flat and plate-like, while dendrite snowflakes have six branches.
7. No two snowflakes follow the same exact path through the clouds, so they all have slightly different shapes.
8. Snowflakes form when water vapor freezes onto a tiny particle in the air, such as a dust grain or pollen.
9. Snowflakes form at temperatures between 0°C and -20°C.
10. Snowflakes can be white, blue, green, or even purple, depending on the conditions in which they form.