The Smell After Rain
Written by Studio AM.
Your result
- Words per minute
- Score
- Pace
Words per minute mean something only with the score beside them. They describe this passage on this read. With fewer than 3 right, try the next slower pace.
Choose a pace and select Start. The passage is paced and timed, then the questions check what you understood. How pace mode works
Reading time 0:00
After rain reaches dry ground, the air may carry an earthy smell called petrichor. The scent does not come from water alone. Plants leave oils on soil and stone during dry weather. Certain soil bacteria also produce a compound called geosmin.
One way this scent can enter the air begins when a raindrop hits a porous surface, tiny air bubbles can form beneath it. The bubbles rise through the drop and burst. They release a fine mist of particles into the air. Those particles can carry geosmin and plant oils toward a person's nose.
Light rain can produce the effect especially well because drops strike gently enough to trap bubbles. Faster impacts can leave too little time for bubbles to form, so heavier rain may produce fewer airborne particles. Wind, soil type, and the length of the dry spell also change what people smell. Petrichor is therefore not the odor of rain itself. It is a brief airborne mixture released when rain meets a particular landscape.
The passage is hidden while you answer. It comes back with your result.
Questions
Choose an answer. The explanation appears after you answer.
-
Question 1 of 4
What is the main idea of the passage?
The answer is A: Petrichor forms when raindrops release soil compounds and plant oils into the air.
The passage traces the scent from materials on the ground through bubbles and airborne particles.
-
Question 2 of 4
Why can light rain produce a strong effect?
The answer is B: Its drops can allow enough time for trapped bubbles to form and burst.
The final paragraph explains that faster impacts may leave too little time for bubbles to form.
-
Question 3 of 4
What does “airborne” mean?
The answer is C: carried through the air
The particles travel into the air and toward a nose, so airborne means carried in air.
-
Question 4 of 4
What compound is produced by certain soil bacteria?
The answer is D: geosmin
The opening paragraph directly identifies geosmin as a compound made by some soil bacteria.
Score: none answered yet.