Open vs. Closed Systems
Open vs. Closed Systems is a Grade 7 science concept from Amplify Science (California) Chapter 3: Accounting for Atoms, demonstrating that matter is conserved in chemical reactions. By burning steel wool in a sealed jar (closed system), students see that total mass remains constant because atoms that escape as gas in an open system are still present — they have just changed form.
Key Concepts
To verify that matter remains, scientists use closed systems where nothing can escape. If you burn steel wool inside a sealed jar, the total mass stays exactly the same.
This experiment provides proof that atoms are not lost; they are just transforming into products that might be difficult to capture in an open system .
Common Questions
What is the difference between an open and closed system in chemistry?
In an open system, matter can escape to the surroundings (like gases escaping a burning reaction), making it seem like matter disappears. In a closed system, nothing escapes, so all matter is contained and total mass stays constant.
Why do scientists use closed systems to study conservation of matter?
Closed systems prevent matter from escaping, so scientists can verify that total mass before and after a reaction is unchanged. This provides direct proof that atoms are conserved and not lost.
What happens when steel wool burns in a sealed jar?
The steel wool reacts with oxygen inside the jar to form iron oxide. Since the jar is sealed, no matter escapes, and the total mass of the jar and its contents remains the same before and after burning.
What do Grade 7 students learn about open and closed systems in Amplify Science?
In Chapter 3 of Amplify Science California Grade 7, students use sealed container experiments to demonstrate the law of conservation of matter, showing that atoms are not lost — they just rearrange into new products.