Our World
Why Can’t Humans Breathe Underwater?
Water contains oxygen, so why can’t our lungs use it?

The short answer
Water contains dissolved oxygen, but human lungs are designed to take oxygen from air.
Let’s explore
- Water contains dissolved oxygen, but human lungs are designed to take oxygen from air.
- Fish have gills that can obtain dissolved oxygen from water.
- Humans need equipment such as scuba gear if we want to breathe while underwater.
Quick Quiz
- What is the short answer to “Why Can’t Humans Breathe Underwater?”?
- Can you explain one key fact in your own words?
- What new question would you like to explore next?
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Why Is the Sky Blue?
Sunlight looks white. So why does the sky look blue?
Sunlight contains many colors.
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How Does a Rainbow Form?
How does white sunlight become a rainbow of colors?
Sunlight enters tiny water droplets. The light bends, reflects inside the droplet, and bends again as it leaves.
Our World
Why Does the Moon Seem to Follow Our Car?
Have you ever felt as though the Moon is following your car?
Nearby trees, houses and road signs appear to move quickly because they are close to us.
