Petrichor

High school (ages 12+)
Environment & Earth

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/petrichor

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the etymological origin?Ancient Greek 'petra' (rock/stone) and 'ichor' (the blood of the gods)
2. What is the year of scientific definition?1964
3. Why does petrichor smell stronger after a long dry spell?During dry periods, plants release oils and soil bacteria produce geosmin, which build up on rocks and soil. When rain finally hits, these chemicals are released into the air, making the scent more noticeable.
4. How do scientists know what makes petrichor?Scientists studied the chemicals that come out of dry soil when it gets wet. They found that plant oils and geosmin are the main contributors to the scent.

Petrichor: The characteristic earthy scent produced when rain falls on dry soil, a result of released volatile compounds.
Actinobacteria: A phylum of bacteria, many of which are soil-dwelling and produce geosmin, contributing to the smell of petrichor.
Geosmin: A volatile organic compound produced by microorganisms, responsible for the distinct earthy aroma associated with petrichor.
Aerosol: A colloidal system in which fine solid particles or liquid droplets are dispersed in a gas, such as the mist carrying petrichor compounds.