Explain what a 'closed system' (also called an 'isolated system') is according to the video, and what its key characteristic is regarding matter and energy.

A closed or isolated system is a system where there is no movement of energy or matter into or out of that system. In such a system, conservation laws apply, meaning the amount of energy, charge, or momentum (and by extension, matter) within it stays the same.

Using the Lego example from the video, explain how the concept of conservation applies to the number of Legos.

In the Lego example, if you start with seven Legos and put them together or take them apart within a defined system, the number of Legos remains seven. The Legos are conserved as long as no Legos enter or leave the system.

Why is it important to correctly define a system (as either open or closed) when you are trying to understand if something, like the amount of matter, is conserved?

It is crucial to correctly define a system because conservation laws only apply to closed (or isolated) systems. If the system is open, matter or energy can enter or leave, meaning the amount of matter or energy inside will not stay the same.

The Law Of Conservation Of Mass Lesson Plan for 8th Grade

Free to teach as-is — the teacher guide, student handout, and slides are included.

Teaching a different level? Adapt this lesson →

Free — we'll email you an access link. Google Docs format.

Objective

I can explain the law of conservation of mass.

Part 1 of 4

Warm-up video

Bozeman Science · 4:53Vetted channel

We don't generate video — this one is by Bozeman Science on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.

Part 2 of 4

Key concepts

3 concepts

1
Conservation means that something stays the same within a defined system.
2
For conservation laws to apply, a system must be closed or isolated, meaning no matter or energy can enter or leave.
3
In a closed system, quantities like energy, charge, and momentum are conserved.

Part 3 of 4

Practice

10 questions

Based on the video, what does the term 'conservation' mean?

Describe an 'open system' as defined in the video, and explain what can happen to matter and energy in such a system.

Part 4 of 4

Exit ticket

Quick comprehension check

“Based on the video's explanation of closed systems, what happens to the amount of matter inside a system if it is closed or isolated? Explain your answer.”

Sample answer included in the free materials

Get the materials

Teacher guide, student handout, and slides — free, in Google Docs format

Teacher Guide
Complete lesson plan with answer keys and alternate activities
Student Handout
Printable worksheet
Slides
Ready to present

We'll ask for your email to send your access link — nothing else.

Teaching a group at a different level?

Where are your students right now? We'll rebuild this lesson to match — including the teacher guide, student handout, and slides, saved to your Google Drive.

Adapt This Lesson

The Law of Conservation of Mass

Objective

Warm-up video

Key concepts

Practice

Exit ticket

Get the materials

Teaching a group at a different level?

Related lessons

Mitosis the Way Cells Divide

Making Data Tables in Science

Counting Valence Electrons