Unit Overview

In this unit about states of matter, students solve two mysteries: one on freezing frogs and another on rising and shrinking lake water levels. They then experience  a lab in which they gather evidence to prove that that gases, liquids, and solids all consist of particles that behave differently in different states. The unit culminates in an engineering challenge in which students are tasked with applying their knowledge to solve to a phase-change-related problem in the city of Particleville.

  • Lesson 1
    Lesson 1: Solve: Freezing Frogs + Missing Water Mystery

    Solve: Freezing Frogs + Missing Water Mystery

    Choose to solve a live video mystery on freezing frogs or an animated mystery on why the lake levels change throughout the year. By the end of The Solve, students will understand that substances exist in different states of matter, which are characterized by the substance's molecular behavior. (Live Solve: 65-95 minutes; Animated Solve: 80 minutes)

  • Lesson 2
    Lesson 2: Make: Lab Stations: Experience States of Matter

    Make: Lab Stations: Experience States of Matter

    Learners explore the different states of matter through a series of lab stations, making observations and coming to conclusions about what their observations mean for particle motion in different states. (100 minutes)

  • Lesson 3
    Lesson 3: Engineer: Use States of Matter Knowledge to Solve a Problem in Particleville

    Engineer: Use States of Matter Knowledge to Solve a Problem in Particleville

    The city of Particleville is having some problems: excessive potholes, a desperate demand for fresh water, and a tired balloon artist who needs help blowing up all his balloons! Building off what they learned in the “Make” and the “Solve,” learners design a solution to one of Particleville’s problems. (150 minutes)

  • Next Generation Science Standards
    Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed. [Clarification Statement: Emphasis is on qualitative molecular level models of solids, liquids, and gases to show that adding or removing thermal energy increases or decreases kinetic energy of the particles until a change of state occurs. Examples of models could include drawing and diagrams. Examples of particles could include molecules or inert atoms. Examples of pure substances could include water, carbon dioxide, and helium.]
  • Inquiry Scale
    • Each lesson in the unit has an Inquiry Scale that provides directions on how to implement the lesson at the level that works best for you and your students.
    • “Level 1” is the most teacher-driven, and recommended for students in 4th-5th grades. “Level 4” is the most student-driven, and recommended for students in 7th-8th grades.
    • For differentiation within the same grade or class, use different inquiry levels for different groups of students who may require additional support or an extra challenge.
  • Common Misconceptions
    • Learners often confuse an increase in particle motion with simply having fewer molecules (more space to move).
    • Learners initially think that a solid, liquid, and gas are completely different substances when in fact they have the same molecular composition.
    • Learners often think that the molecules themselves are expanding or contracting depending on their state, when it is really the substance that expands or contracts due to the motion of molecules.
  • Vocabulary
      • State
      • Liquid
      • Solid
      • Gas
      • Melt
      • Freeze
      • Evaporate
  • Content Expert
    • Hans C. von Baeyer
      Chancellor Professor of Physics, Emeritus College of William and Mary
  • Leveled Reading

    * To give our users the most comprehensive science resource, Mosa Mack is piloting a partnership with RocketLit, a provider of leveled science articles.

    • Gas - The Crazy Kids

      In this article, students will explore the properties of gases. They will look how these molecules independently move and collide. The article also discusses how volume and pressure in a gas can change.

    • Matter Changes

      With a little more or a little less heat, everything can change. In this article, we explore how heat changes matter from solid, liquid, gas, and plasma.

    • It's Not Magic . . . It's Just a Phase

      In this article, students investigate the concepts of freezing point, boiling point, and melting point through a magic trick. They'll read about how a magician makes water change phase through heating and cooling at each of these temperatures.

    • If I Freeze or Boil You, You Won't Change?

      In this article, students read about the difference between a chemical change and a physical change. They learn that in a physical change, a substance will change the way it looks, but this won't change what it is.

    • Solid!

      This article explores the formation and structure of a solid. Students will look at the concept of a repeating pattern and the lattices that hold together all of the building blocks that make up a solid.

    • Waiting For Water

      In this article, students read about the basics of fluids and their behaviors. They read about the basics of flow, fluid, condensation and the attractive forces that hold things together in liquids and solids.