What is the longest human bone and do orcas sleep? Try our kids’ quiz

Illustration: Hennie Haworth/The Guardian

1. Patrick, 7, asks: what is the longest bone in your body?

   1. The spine

   2. The humerus

   3. The femur

   4. The tibia

2. Robin, 4, asks: why is the thing we wash our hair with called shampoo?

   1. It’s from the ancient Greek sampou which meant soap

   2. It was invented for an ad: “Shampoo kalamazoo you can have clean hair, too!”

   3. It was invented in Victorian times by a man named Mr Albert Shampoo

   4. It’s from an old Hindi word meaning kneading

3. Ruaridh, 3, asks: do orca whales sleep? If so, where?

   1. Only one half of an orca’s brain goes to sleep, and they sleep with their pod

   2. Orcas take turns sleeping in the middle of their pod

   3. Orcas sleep on sandy banks

   4. Orcas don’t need sleep

4. Evangeline, 8, asks: why is there no air on the moon?

   1. Because it’s so porous that all its air is absorbed

   2. Because there are no trees on the moon to make oxygen

   3. Because it’s much older than the Earth, so all of its air has been used up

   4. Because it doesn’t have a large enough mass

5. Leo, 6½, asks: how is a felt tip pen made?

   1. Paintbrush ends are connected to ink cartridges and put into plastic pens

   2. Felt cylinders saturated in ink are put into plastic pens

   3. Ink cartridges are attached to felt drawing tips and put into plastic pens

   4. A tube of water is attached to a coloured pencil and put into a plastic pen

Solutions

1:C - The femur, or thigh bone, is the longest bone in the human body. The longest ever recorded belonged to a German man known as Constantin the Giant and it was 76cm (2ft 6in) long., 2:D - The word shampoo comes from the Hindi champo which means to knead or massage. The word came over to Britain during the colonialist era and began to be used in the 19th century in terms of hair washing. The product takes its name from the action., 3:A - Orcas can’t fully sleep the way humans can because they need to be awake to breathe. Instead, they allow half their brain to fall asleep. The whole pod huddles together and gently cruises forwards on the surface of the sea while they rest., 4:D - The moon is much smaller than the Earth, so it doesn’t have as strong a gravitational pull to hold on to an atmosphere., 5:C - Felt tip pens are made from felt drawing tips that are attached to ink cartridges. The felt is usually made from synthetic fibres pressed together. The ink travels from the cartridge through the tip and on to the page.

Scores

1. 5 and above.

2. 4 and above.

3. 3 and above.

4. 2 and above.

5. 0 and above.

6. 1 and above.

Molly Oldfield hosts Everything Under the Sun, a weekly podcast answering children’s questions, out now as a book.

Does your child have a question? Submit one here