Parts per million

High school (ages 12+)
Mathematics & Numbers

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/parts-per-million

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 definition?One part per million (ppm) is a ratio of 1:1,000,000
2. What is the equivalency?1 ppm = 10⁻⁶ = 0.0001%
3. What does "parts per million" mean?It is a way to say one tiny piece of something in a million pieces of everything else. It helps scientists talk about very small amounts.
4. Why do scientists use ppm instead of percentages?Because percentages are too big when the amount is very small. Ppm lets them see tiny amounts that still matter.

Dimensionless unit: A unit that does not have physical dimensions, used for ratios and proportions.
Dilute concentration: A solution where the amount of solute is very small compared to the solvent.
Analytical chemistry: The branch of chemistry concerned with identifying and quantifying the chemical substances present.