Which process converts nitrogen gas (N₂) from the atmosphere into ammonia (NH₃) that plants can use?
MCQ + FRQ
AP Environmental Sci
Ecosystems, pollution, and 3 free-response problems.
7practice MCQs
1FRQ prompts
1–5scaled scoring
Freeno paywall
What's in APES
Every unit is mapped to the official Course and Exam Description.
U1Living World: Ecosystems
U2Living World: Biodiversity
U3Populations
U4Earth Systems
U5Land & Water Use
U6Energy Resources
U7Pollution
U8Global Change
Try a few sample questions
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Difficulty
Skill
Which of the following is a renewable energy source?
Which pollutant is primarily responsible for acid rain?
Which greenhouse gas has had the greatest cumulative contribution to anthropogenic climate change?
Sample FRQ · AI graded
FRQ prompt
Free Response Question: A town of 50,000 people currently relies on a coal-fired power plant that produces 200 MW of electricity. The town is considering transitioning to solar and wind power. (a) Identify two environmental advantages and one economic challenge of transitioning from coal to solar/wind energy. (b) If the average household uses 1.2 kW of power and there are 20,000 households, calculate the minimum power generation needed to serve only residential users. Show y…Practice full FRQs
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