The Environment quiz

More questions about The Environment

These visible examples show the question style. LearnClash turns the full topic into ranked duels and spaced repetition.

1. 1 Easy

   What gas makes up about 78 percent of Earth's atmosphere?

   Answer: nitrogen

   Why: Dry air is 78.08 percent nitrogen, 20.95 percent oxygen and 0.93 percent argon, so argon alone outweighs every remaining trace gas put together.

2. 2 Medium

   Which item have volunteers collected most often in beach cleanups since 1986?

   Answer: Cigarette butts

   Why: Volunteers logged 65,632,086 of them since 1986, still first all time, though plastic drink bottles topped the 2025 cleanup.

3. 3 Hard

   Why does Pando, a Utah forest, count as one organism?

   Answer: One shared root system

   Why: Pando is Latin for I spread: its stems live only 100 to 130 years each, yet the shared roots keep regrowing them across 106 acres.

4. 4 Easy

   Why do ocean corals turn stark white during a bleaching event?

   Answer: They expel symbiotic algae

   Why: The expelled zooxanthellae algae provide up to 90% of a coral's energy, meaning bleached corals quickly starve unless waters cool down.

5. 5 Medium

   Roughly how long does nature take to form one inch of topsoil?

   Answer: 500 to 1,000 years

   Why: Soil scientists put the range at 500 to 1,000 years per inch, and the FAO reckons a thousand years may yield only a few centimetres.

6. 6 Hard

   What percentage of the world's freshwater is locked in glaciers?

   Answer: 69%

   Why: The USGS pins the exact figure at 68.7 percent, with most of the rest underground, leaving rivers and lakes only a sliver of the total.