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Visualizing States of Matter Mark as Favorite (131 Favorites)

ACTIVITY in Phase Changes, Elements, Mixtures. Last updated January 15, 2021.


In this activity, students will view, sort and classify pure substances and mixtures into the 3 common states of matter found in the laboratory. Students will also discuss their classification system with their teacher and peers.

Grade Level

High and Middle School

NGSS Alignment

This activity will help prepare your students to meet the performance expectations in the following standards:

  • HS-PS2-6: Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.
  • HS-PS3-2: Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles (objects) and energy associated with the relative positions of particles (objects).


By the end of this activity, students should be able to

  • Classify the three states of matter found in the laboratory by molecular level particle representations.
  • Identify differences in the particle representations to classify them as pure substances, both elements and compounds, as well as mixtures.
  • Verbally explain the classification system their group developed.

Chemistry Topics

This activity supports students’ understanding of

  • States of matter
  • Pure substances
  • Mixtures
  • Particle representations of elements and compounds


Teacher Preparation: 30 minutes initially; 5 minutes thereafter

Lesson: 30 minutes

Materials (Per group)

  • Ziplock sandwich bag that contains the following:
    • cutouts of the particle representations
    • 6 - 3x5 index cards labeled: solid, liquid, gas, element, compound, mixture


  • There are no specific safety concerns for this activity.

Teacher Notes

  • This activity was originally designed for high school students. This version is a modification, inspired by the original for use in the middle school classroom as part of the AACT Strategic Plan and the work of the AACT Grade-Level Ambassadors.
  • This activity focuses on using knowledge of the three states of matter that occur in the classroom combined with the student understanding of elements, compounds and mixtures to classify visual representations at the molecular level. This activity can be used at the end of a lesson in a first year chemistry class, or at the beginning of an AP Chemistry class to assess what is already known by second year students. 
  • Students should be in groups of 2 or 3 students and separated as best as possible to allow for individual group ideas and discussion.
  • This can be an effective inquiry-based activity where very little instructions are provided to the students. In this situation, each student group is given a bag and given 10-15 minutes to classify and formulate a response to their method of classification. Remind students that they will have to explain to each other their method(s) of classification.
  • Teachers should circulate the room listening to the individual discussions, if students are not talking and just sorting ask them about their classification method. Expect students to classify the materials in various ways and not necessarily in the design most obvious to the teacher, which is ok, but make them defend it.
  • Depending on the class level, adaptations could have students only classify 1 set of characteristics (state of matter or substance/mixture) or the number of molecular representations could be reduced.
  • The student activity listed below has been used with first year chemistry students. The extension assignment relates the diagrams to real substances. It also allows students to practice technology skills.
  • The particle diagrams should be printed in color and if possible, on cardstock to increase the durability. Also, the diagrams can be laminated to further increase the number of uses out of each set. Finally, the index cards could also be laminated if desired.
  • The cards are available for download and printing. The answer key for card sorting has been provided below:

Element, Compound or Mixture



Element – Monatomic element



Compound – 2 Atom molecules



Compound – 3 Atom molecules



Element – Diatomic element



Mixture – 2 Monatomic elements

Ar & Xe


Mixture – 3 Atom molecule and diatomic element

H2O and Cl2


Mixture – 3 Atom molecule and monatomic element

SFCl and Ar


Mixture – 3 Atom molecule and 2 atom molecule

H2O and HF


Mixture – Monatomic element and diatomic element

Xe & Br2


Mixture – 2 Atom molecule and diatomic element

HF and H2


Mixture – 3 Atom molecule and monatomic element

H2O and Xe


Mixture – 2 Atom molecule and monatomic element

HF and Ar


Mixture – 2 Diatomic elements

Br2 and N2

  • Prelab Answer key:
    • Solid: matter that has definite shape and volume
    • Liquid: a form of matter that flows, has a fixed volume, and takes the shape of its container
    • Gas: matter that has no definite shape or volume; it adopts the shape and volume of its container
    • Element: a substance that cannot be changed into simpler substances under normal laboratory conditions
    • Compound: a substance that can be separated into simpler substances only by chemical reactions
    • Mixture: a physical blend of two or more substances that are not chemically combined
    • Physical Property: a characteristic of a substance that can be observed without changing the identity of the substance
    • Chemical Property: a characteristic of a substance that is observed during a reaction in which the chemical composition or identity of the substance is changed
  • Analysis Answers will vary based on the students classification. The picture in the lab will provide evidence of the answers to the questions.

For the Student



Matter can be classified as either a mixture or a pure substance, which include both elements and compounds. These classifications can occur in all common states of matter found in the laboratory.

Prelab Questions

Define the following terms:







Physical Property:

Chemical Property:


Using the headings on the index cards, develop a method to classify the visual representations.


  1. Using all of the materials found in the bag, develop a method to separate and classify the visual representations.
  2. Once completed, you will be instructed to explain your classification method to the class.


Draw or insert a picture of your classification here. This could be a sketch of your final organization if hand written or it could be an image inserted from your phone if submitting electronically.


  1. Write a short description of how the visual representations were organized by your group.
  2. Upon viewing other group’s organization methods, what changes, if any, would you make to your method? If no changes are necessary, explain why.
  3. List three (3) properties that were used to organize the visual representations.


Using three (3) different visual representations in in the activity in each state of matter, identify and find pictures of the element, compound or mixture that could be represented by the diagrams. Include a picture of the visual representations being identified along with each picture of the substance.