![Mussels on a rocky coastline](/sites/default/files/styles/resource_card_image_360x300_/public/2020-03/mussels-on-rocky-coastline.jpg?itok=4PnEYQCV)
Using Mussels to Monitor the Environment
STEM Explained
Mussels are a kind of invertebrate that filter food out of the water they live in. This makes them a great tool for monitoring environmental water quality and tracking bioaccumulation in aquatic food webs.
![Cartoon leaf holding an umbrella over baby plant](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/cartoon_acid_rain.jpg?itok=J4BMIwgR)
What is Acid Rain?
STEM Explained
Acid rain is any precipitation that has an unusually low pH. It can be rain, snow, fog, etc. But what is a low pH and why is this a problem?
![What are the best materials to use for cleaning water?](/sites/default/files/2019-08/what-are-the-best-materials-to-use-for-cleaning-water.jpg)
What are the best materials to use for cleaning water?
Hands-on Activities
Water is a precious natural resource. What happens if it gets polluted? Learn how water can be cleaned with this hands-on activity?
![What are the effects of acid rain on rocks?](/sites/default/files/2019-08/what-are-the-effects-of-acid-rain-on-rocks.jpg)
What are the effects of acid rain on rocks?
Hands-on Activities
Learn about the chemical reaction that happens between acid rain and limestone.
![Biofuel concept](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/biofuel-concept.jpg?itok=mGz1FUEJ)
What are the Pros and Cons of Ethanol Biofuel?
STEM Explained
Biofuels like ethanol might help fight climate change. But they can contribute to food insecurity and greenhouse gases in ways that might surprise you.
![Aerial of Gas well Marcellus Shale Formation in northern West Virginia](/sites/default/files/styles/resource_card_image_360x300_/public/2020-01/Aerial-of_gas_well.jpg?itok=tjnKvzRe)
What is Fracking?
STEM Explained
The fracking process gets natural gases out of rocks. This process can have effects on freshwater, water quality and even earthquakes!
![Solar panel project in Dakar, Senegal](/sites/default/files/styles/resource_card_image_360x300_/public/2019-11/Solar_project_Dakar%2CSenegal.jpg?itok=q64WAuqV)
What are Carbon Offsets?
STEM Explained
Can carbon offsets help you reduce your environmental footprint, practice sustainable living and fight climate change?
![Hamilton, Ontario industrial area with Toronto skyline in the background](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/the-hamilton-industrial-area-with-toronto-skyline.jpg?itok=shKtb5Tb)
What are Greenhouse Gases?
Backgrounders
This backgrounder explains what greenhouse gases are and how they contribute to climate change.
![Nitrogen symbol from periodic table](/sites/default/files/styles/resource_card_image_360x300_/public/2021-03/the-periodic-table-element-nitrogen.jpg?itok=bs_Xbeg4)
Understanding the Nitrogen Cycle
STEM Explained
What is the nitrogen cycle? How do human activities such as using fertilizer affect the nitrogen cycle? How can this cause greenhouse gases?
![various marine microorganisms as they appear under a microscope](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/marine_microorganisms.jpg?itok=MgdaDkhz)
Marine Microbiology: Meet the Microbes of the Sea!
STEM Explained
The ocean is full of very small but very useful creatures called microbes. Without them, none of the sea plants or animals you’ve seen would exist!
![How can I write secret messages?](/sites/default/files/2019-08/how-can-i-write-secret-messages.jpg)
How can I write secret messages?
Hands-on Activities
Learn how you can write and reveal secret messages in this hands-on chemistry activity.
![How does rain become acidic?](/sites/default/files/2019-08/how-does-rain-become-acidic.jpg)
How does rain become acidic?
Hands-on Activities
Learn how to make a pH indicator and test water samples.
![fancy guppies](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/fancy-guppies.jpg?itok=3im2BfH2)
Guppies, Guppies Everywhere!
STEM Explained
How do different populations adapt to their environment? Let’s explore this concept through guppy speciation.
![Massive algal bloom](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/massive-algal-bloom.jpg?itok=pqgXB2yc)
Eutrophication: Why you should care about pond scum
STEM Explained
When fertilizers from agriculture get into lakes and rivers, big problems can result for aquatic ecosystems, food chains & webs!
![heavy metal band](/sites/default/files/styles/resource_card_image_360x300_/public/2019-09/Heavy_metal_band_0.jpg?itok=-Zc4rYXH)
A Taste of Heavy Metal
STEM Explained
Heavy metal is a term for some toxic chemical elements. They can cause problems like bioaccumulation, but are useful in nuclear medicine and medical imaging.