Q 01/05

Snow crystals form when tiny supercooled cloud droplets freeze around what?

A) Atmospheric particles

B) Falling raindrops

C) Carbon dioxide bubbles

D) Ozone molecules

Answer · why

A) Atmospheric particles

The droplets are only about 10 micrometres across; the crystals then grow by attracting more supercooled water.

Q 02/05

Ice is clear, so why does snow look white?

A) Snow absorbs all colours except white

B) Light scatters off the crystal facets and imperfections

C) Snow contains dissolved air that is white

D) Snow crystals are coated in frost

Answer · why

B) Light scatters off the crystal facets and imperfections

Diffuse reflection sends every wavelength back out at once, which our eyes read as white.

Q 03/05

How many sides does a classic snow crystal have?

A) Four

B) Six

C) Five

D) Eight

Answer · why

B) Six

Water molecules lock together in a hexagonal lattice as they freeze, so the crystal grows six arms.

Q 04/05

Roughly how many water molecules make up a typical snowflake?

A) Ten billion (10^10)

B) Ten trillion (10^13)

C) Ten quintillion (10^19)

D) Ten million (10^7)

Answer · why

C) Ten quintillion (10^19)

They are added to the core at different rates and in different patterns as the flake tumbles through changing conditions.

Q 05/05

Which Vermont farmer began photographing snowflakes under a microscope in 1885, revealing their variety?

A) Wilson Bentley

B) Ukichiro Nakaya

C) Johannes Kepler

D) Kenneth Libbrecht

Answer · why

A) Wilson Bentley

He photographed thousands over his lifetime and was known as 'Snowflake' Bentley.