The Life Starter
Sign up
All courses/Life

Course 237 · Life course 59

Understand Matter with Particle Models

A particle-model notebook explaining states, mixtures, elements, compounds, mass conservation and a physical separation plan from supplied materials. Six introductory lessons use supplied practice cases.

Before you start

Use paper or a free text document; every core input is supplied in the lessons.

Scientific Reasoning and Lab Readiness See everything you’ll need

Free download · Original practice data · No external account required. Download the starter pack

What you’ll leave with

A particle-model notebook explaining states, mixtures, elements, compounds, mass conservation and a physical separation plan from supplied materials.

Start course Start without an account. Sign in to save lesson progress across devices.

Your project

Start with the practice files. Build your project one lesson at a time.

Practice files are free without an account. Sign in to save your project record in My Proof: a description, checklist, and optional work link. Keep the original files in your own app or notebook; saving a project record does not upload them.

  1. Get your materialsDownload practice filesSupplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.
  2. Make your projectView the project checklist Work in your own notebook, document, or software. Use the supplied practice examples when you prefer.
  3. Keep a private recordSave a project record Sign in to save a description and checklist, then return to update them.
Course handbook

Know the route before you begin.

Here’s what you’ll need and what you’ll make. You can return to this guide during any lesson.

Who this is for

Learners aged 14+ building subject foundations and practical independence. Adults can use the same supplied cases.

Prepare before lesson one
  • Use paper or a free text document; every core input is supplied in the lessons.
  • A basic calculator is optional; show the method, units and checks.
  • Suggested earlier course: Scientific Reasoning and Lab Readiness
Your final project

Finish with proof you can use.

A particle-model notebook explaining states, mixtures, elements, compounds, mass conservation and a physical separation plan from supplied materials.

Save a project record in My Proof
See project checklist and review criteria

Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.

What to include

  • Separate measurements from particle explanations.
  • Compare solid, liquid and gas models without inflating individual particles.
  • Classify all supplied element, compound and mixture drawings.
  • Name state transitions while preserving substance identity.
  • Balance the supplied closed-system mass stores.
  • Choose paper separation methods by recovery goal and complete changed cases.

Review and revise

Use these criteria to check your work and choose what to improve.

  • Method: applies the course-specific rules to the supplied cases with visible intermediate work.
  • Accuracy: results agree with the stated facts, units, boundaries and independent checks.
  • Reasoning: explains why the result follows and identifies a limitation or unresolved question.
  • Transfer: completes changed cases and revises the final project when a relevant assumption changes.
Three ideas to help you along the way
Three useful ideas

The rules behind the steps.

01

Use the supplied mechanism

An observable property can be measured or described at the sample scale, such as mass, volume or color. A particle model explains those observations using atoms or molecules. Do not confuse one observation with proof of an entire microscopic structure. Models must agree with observations and can remain incomplete.

02

Connect the middle steps

An element contains one type of atom; a compound contains chemically combined atoms of different elements in a fixed composition; a mixture contains more than one substance without requiring a single fixed chemical composition. A sample can contain many atoms and still be one element. Particle variety alone is not enough: identify bonding and substance identity.

03

Explain the final boundary

A physical separation uses a difference in properties without requiring a new substance. A filter can retain sufficiently large insoluble particles while fluid passes; dissolved particles usually pass ordinary filters. Evaporation can leave a nonvolatile dissolved solid, but loses the solvent unless it is captured. Choose the method for the stated recovery goal, and use this as paper reasoning only.

What do these words mean?
Key words

Key terms worth knowing.

Particle model
An explanation using atoms or molecules to represent sample behavior.
Element
A substance containing one type of atom.
Compound
Different elements chemically combined in a fixed composition.
Mixture
More than one substance present together.
Closed system
A stated boundary with no matter entering or leaving.
Filtration
Separation through differential passage of material through a filter.
Your route

6 lessons.
One useful project.

Work in order the first time. Each lesson makes something the next lesson can use.

  1. 1
    Up next

    Separate observations from particle explanations

    Distinguish sample-scale observations from particle explanations and unsupported conclusions.

  2. 2
    9 min

    Use particles to compare states

    Relate particle spacing and motion to the supplied solid, liquid and gas behaviors.

  3. 3
    10 min

    Classify elements, compounds and mixtures

    Classify supplied particle drawings by atom types, bonding and substance variety.

  4. 4
    9 min

    Explain a state change without inventing a new substance

    Name state transitions and explain them with preserved particle identity.

  5. 5
    9 min

    Track matter in a closed model

    Account for all mass stores within a stated closed boundary and explain a redistributed amount.

  6. 6
    13 min

    Choose a physical separation from properties

    Select a paper separation method from supplied properties and the fraction to recover.

Use the tools

Tools to help you practice.

See all tools
ZIP · practice files

Understand Matter with Particle Models practice files

Supplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.

Text worksheet

Your course project worksheet

A downloadable text worksheet with each lesson’s working output, space for your answers, and the shared final-project checklist. Save your own copy.

Source transparency

Sources and further study.

Explore the references behind the lessons and take your learning further. Source notes explain access and reuse.

OpenStax: phases and matter classification
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

OpenStax: physical and chemical properties
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

OpenStax: atoms and symbols
Source & access notes · checked 2026-10-01

Web open/search showed the official page, its topic heading and relevant concept description. This is a content/source check, not a provider endorsement.

Access: Official page retrieved with the web reader on 2026-10-01; interactive tools and videos were not certified by retrieval.

Reuse: Original fictional teaching cases, calculations, questions and examples; link and short factual paraphrase only. No copied source exercises or illustrations.

Ready when you are

Start with the first useful move.

You’ll always know what to do, what to make, and where to go next.

Start lesson one