Q 01/05

If a marble were scaled up to stand for one nanometer, a meter would be about as big as what?

A) The Moon

B) Mount Everest

C) The Earth

D) The Sun

Answer · why

C) The Earth

The Earth is to a marble roughly what a meter is to a nanometer, and even the smallest bacteria are about 200 nanometers long.

Q 02/05

Which part of the human body grows at a rate of roughly one nanometer every second?

A) Fingernails

B) Scalp hair

C) Beard hair

D) Wisdom teeth

Answer · why

A) Fingernails

Fingernails grow about one nanometer per second, a length that just three gold atoms lined up would span.

Q 03/05

Which lizard scales glass on toe hairs whose nanoscale tips cling by van der Waals forces?

A) Chameleon

B) Gecko

C) Iguana

D) Skink

Answer · why

B) Gecko

Gecko toes carry millions of hairs called setae, and each one branches into about 1,000 flat tips only around 200 nanometers wide.

Q 04/05

Self-cleaning paints copy the water-shedding nanoscale texture on the leaves of which flower?

A) Orchid

B) Tulip

C) Magnolia

D) Lotus

Answer · why

D) Lotus

Lotus leaves make water bead up and roll away with the dirt, a self-cleaning trick botanist Wilhelm Barthlott worked out with an electron microscope i...

Q 05/05

Zinc oxide nanoparticles let which everyday product rub in clear instead of leaving a white film?

A) Sunscreen

B) Moisturizer

C) Lip balm

D) Hand soap

Answer · why

A) Sunscreen

Sunscreen with nanoscale zinc oxide still soaks up the sun's burning rays but lets visible light pass, so the chalky look disappears.