Air Under Snow

In the picture

1. 11. The person’s cheek.
2. 22. The clear bubble around the face.
3. 33. A blue dot inside the bubble.
4. 44. A grey dot inside the bubble.

Examples

• A plastic bag over your head traps air.
• Holding your breath under a blanket.

Quiz: Air Under Snow (Age 12)

1. 1

   Why can a small air pocket under snow stop keeping someone alive after a short time?

   • The air is not replaced, so oxygen runs out and carbon dioxide builds up.
   • The air becomes too cold to use, so the body cannot take oxygen from it.
   • The air is slowly pushed out by the weight of the snow.
2. 2

   In a sealed air pocket under snow, what happens to the oxygen over time?

   • It stays the same because the pocket is sealed.
   • It decreases because the person keeps breathing it and no fresh air comes in.
   • It increases because the person breathes out oxygen.
3. 3

   In a sealed air pocket under snow, what happens to carbon dioxide over time?

   • It is absorbed by the snow, so it cannot build up.
   • It stays at a safe level because the pocket is small.
   • It builds up because the person breathes it out and it cannot escape.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.