States of Matter

Overview

This 40-minute lesson is designed for a small group of 3 seventh-grade students to explore the properties and states of matter in alignment with the Common Core State Standards and Next Generation Science Standards (NGSS). The lesson prioritizes inquiry-based learning, hands-on activities, and critical thinking skills to deepen understanding of matter and its interactions.

Standards Alignment

Next Generation Science Standards (NGSS) (widely adopted and paired with Common Core practices in science education):

MS-PS1-1: Develop models to describe the atomic composition of simple molecules and extended structures.
MS-PS1-2: Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
MS-PS1-3: Gather and make sense of information to describe that synthetic materials come from natural resources and impact society.

Common Core State Standards (CCSS) for Literacy in Science and Technical Subjects:

CCSS.ELA-LITERACY.RST.6-8.3: Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.
CCSS.ELA-LITERACY.WHST.6-8.7: Conduct short research projects to answer a question (including a self-generated question), drawing on several sources and generating additional related, focused questions.

Learning Objectives

By the end of this lesson, students will be able to:

Describe the three main states of matter (solid, liquid, gas) and key properties of each.
Explain how matter changes state through heating and cooling (melting, freezing, evaporation, condensation).
Develop and use a simple model demonstrating particle arrangement in solids, liquids, and gases.
Follow scientific procedures to observe and record physical changes in matter during a controlled experiment.
Communicate findings clearly through writing and discussion.

Materials Needed

Clear plastic cups (3 per student)
Ice cubes
Water (room temperature and warm)
Balloons
Stove or hot plate
Thermometer
Chart paper and markers
Science notebooks or worksheets
Timer or stopwatch

Lesson Breakdown (40 minutes)

1. Engage (5 minutes)

Begin with a quick thought experiment: Ask students to describe what happens to water when it freezes and when it boils (encourage them to think of familiar examples like ice in a drink or steam from a kettle).
Show a balloon partially filled with air and ask what they think is inside and why it holds its shape.

2. Explore (15 minutes)

Experiment Stations (Rotate together to keep engagement tight for 3 students):
1. Solid to Liquid: Students observe melting ice cubes and record temperature changes every 2 minutes using the thermometer.
2. Liquid to Gas: Heat water to observe evaporation carefully (teacher-supervised). Students watch steam rise into the balloon and predict changes.
3. Gas Behavior: Compare an inflated vs. deflated balloon and discuss air particles.
Prompt students to note changes and ask guiding questions about particle movement and energy changes.

3. Explain (10 minutes)

Using chart paper, work with the students to create a particle model sketch of solids, liquids, and gases based on observations.
Introduce vocabulary: molecule, particle, kinetic energy, melting, freezing, evaporation, condensation.
Tie observations to explanations on how heating or cooling affects particle behavior and state changes.

4. Elaborate (5 minutes)

Small group discussion: Have students generate one question about matter that they are curious about and think about everyday effects of state changes (e.g., why do puddles dry up?).
Model how to do a brief research entry in their science notebooks addressing one question, identifying sources of information (e.g., textbooks, classroom materials).

5. Evaluate (5 minutes)

Quick-write: Students write a paragraph summarizing what they observed during the experiments and explaining the particle model of matter.
Share short presentations aloud to practice communication aligned with CCSS speaking and listening standards.

Differentiation & Extensions

For students who grasp concepts quickly, introduce plasma and discuss other states of matter briefly.
For struggling learners, provide sentence starters and diagrams to help structure their explanations.
Extend learning by assigning a home experiment (e.g., observing condensation on a cold drink) and writing a journal entry.

Assessment

Observation of students’ participation and accuracy during experiments
Review of quick-writes for conceptual understanding and use of scientific vocabulary
Informal oral presentations to check communication skills and content mastery

Teacher Reflection

Did the students successfully connect particle models with observable phenomena?
Were the experiments conducted safely and efficiently within the tight timeframe?
Which part generated the most curiosity and how can that be leveraged for future lessons?

Teaching Instructions