Hands-on Activity States of Matter

Learning Objectives

After this activity, students should be able to:

• Describe the three states of matter.
• Explain that physical properties of matter can be measured (such as temperature, mass, volume, density, etc.).
• Explain the concept of evaporation.
• Identify the temperature at which water boils.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

To share with the entire class:

• LEGO MINDSTORMS NXT Education Base Set (such as part #2095 for $159.98, available at https://shop.education.lego.com/legoed/education/NXT/NXT+Base+Set/5003402&isSimpleSearch=false; this set includes the 3 motors, wires and LEGO NXT brick needed for this activity)
• LEGO NXT temperature sensor ($27.96, available at https://shop.education.lego.com/legoed/education/NXT/NXT+Temperature+Sensor/9749&isSimpleSearch=false)
• ice cubes, 3 lbs (1.4 kg)
• metal pot
• hot plate or stove
• laptop computer on which to record/display data
• any cables required to connect NXT brick to computer
• States of Matter Pre-Assessment, one per student
• States of Matter Data Sheet, one per student
• States of Matter Post-Assessment, one per student

Worksheets and Attachments

Pre-Req Knowledge

Familiarity with the three states of matter, physical properties of matter, using the five senses to identify matter, and measuring temperature.

Introduction/Motivation

Today, we will act as employees of a chemical engineering company and explore the various properties of water in different forms. Chemical engineers often deal with water (a liquid), ice (a solid) and water vapor (a gas) in their everyday work life. Most of our electricity comes from power plants that use the energy of steam (water vapor) to generate electricity. Steam is obtained by heating liquid water to very high temperatures to boil water.

As chemical engineers, we must know the temperature at which water boils and produces steam. Therefore, we will study how different forms of water behave under hot temperatures in order to discover the temperature at which water boils.

We will start with ice and observe how it behaves when exposed to a heat source (an electrical stove). Since we work for an engineering company, we would like to measure the temperature of our matter in an efficient way. We won't use a thermometer because thermometers cannot be used in a chemical plant where water is boiled in large quantities. In real-world industrial applications, thermometers are not used because that requires a person to manually take temperature readings. Imagine if your job was to sit a read a thermometer all day long? That doesn't sound like fun! Instead, temperature sensors are used and connected to computers and robots to automatically take temperature readings and record them. This is a far more efficient process.

For our activity, we wish to be safe and away from fire. Therefore, just like in a real chemical plant, we will use a robot to monitor the temperature and give us continuous temperature readings.

Today we will visually confirm the three states of water. We will start with water in its solid state (also known as ice), then apply heat to melt the ice. As the ice melts, our temperature-bot will monitor the temperature. What is your prediction? Will the temperature increase or decrease as ice is melted? We will continue melting the ice until it all melts and turns into liquid water. Then you will monitor the temperature as the liquid water begins to boil. How can you tell the water is boiling? You will be able to see the steam and recognize that steam is the third form of matter (gas).

Remember - our goal in this activity is to identify the boiling temperature of water from the temperature-bot reading in order for our steam power plant to operate successfully.

Procedure

Background

Students act as "chemical engineers" at a power plant facility that produces steam continuously by melting ice to water and then boiling liquid water to produce steam. The steam provides power to a motor, which in turn provides electricity for our homes. The engineering challenge for students: The engineers need to find out the temperature at which water boils and it is our responsibility to solve this problem by running an experiment. Students collect and analyze data from a temperature sensor that continuously displays temperature readings for them to closely monitor. Determining properties of matter plays a crucial role in industrial applications and these properties usually vary with different types of matter. For example, water and milk boil at different temperatures. It is important to pay close attention to these physical properties of matter since they are used in real-life applications.

Matter exists in three states: solid, liquid or gas. Students are introduced to matter by using their five senses to identify matter. They can also identify matter by its physical properties (such as shape, size, color, weight, etc.) except for certain types of gases. Students are shown that states of matter can be easily changed from solid to liquid to gas by melting ice on a stove, then by boiling water to change liquid to gas. A temperature sensor on a LEGO NXT robot enables students to determine the physical property of ice, liquid water, and water vapor, as well as identify the boiling point of water.

Before the Activity (for instructors)

• Gather materiails and make copies of the States of Matter Pre-Assessment, States of Matter Data Sheet and States of Matter Post-Assessment.
• Build a robot that incorporates a temperature sensor to monitor data. For instructions on assembling a simple robot, see: http://www.nxtprograms.com/NXT2/five_minute_bot/index.html. Be sure that the temperature sensor is attached to a motor and connected to the NXT brick.
• Make sure that all NXT brick battery packs are fully charged.

With the Students

1. Give students 10 minutes to complete the pre-assessment handout. Then collect them.
2. Discuss the experimental set-up and give students a rundown of the procedure.

   

3. Review the pre-assessment with the entire class.
4. Review with students the different states of matter and properties. What is the definition of a solid, a liquid, a gas? Review keywords and their definitions.
5. Ask the students: How can the physical properties be measured in each state? (Solids and liquids can be weighed easily; gases cannot. Temperature can also be measured easily using temperature sensors. Physical dimensions can be measured for solid objects, such as ice cubes.)
6. Introduce the temperature sensor and demonstrate how it will be used during the experiment. (A temperature sensor works similar to a thermometer but can give digital reading through the NXT once it is connected to the device. To demonstrate how the temperature sensor is used, download and run Temp_sensor_display.rbt on to the NXT brick.)
7. Place the ice into a pot (about three pounds or 1.4 kg of ice)
8. Identify the state of matter of ice. (solid)
9. Place the pot on a hot plate or stove.
10. Place the temperature sensor inside the pot. Then, turn on the heat.
11. Turn on the NXT brick and use the NXT 2.0 data logging program to collect data.

    

• The NXT data logging program automatically displays the data in a temperature vs. time graph on the computer, therefore no programming is required. The data logging software must be configured to the correct port that the temperature sensor is connected to in the NXT brick. Set the temperature unit to Celsius.
• Once the data logging software is running, the graph on the computer should give a temperature reading of 0° C.

12. Once the NXT is continuously recording data, turn on the heat source.
13. Once all the ice is melted, identify this state of matter. (liquid)
14. Note that the temperature rises as the water is heating up.
15. Once the water starts to boil and steam is observed rising, identify the state of matter of this water vapor. (gas)
16. Record the temperature of the boiling point of water.
17. The temperature of boiling water can be identified from the graph and stays constant at 100° C.
18. After students record the correct boiling point of water (100° C) and identify the three states of matter (solid, liquid, gas), review the key activity point: You have now correctly identified the temperature at which water boils, which is necessary to know in order for the steam plant to operate.

Vocabulary/Definitions

condensation: The process of gas changing into liquid.

evaporation: The process of liquid changing into a gas.

freezing: The process of liquid changing into solid.

gas: Matter that has no definite shape or volume.

liquid: Matter that has a volume that stays same, but a shape that can change.

matter: Anything that takes up space.

melting: The process of solid changing into gas.

physical property: Anything that you can observe about matter by using one or more of your senses.

solid: Matter with a volume and shape that stays the same.

Assessment

Pre-Assessment:

Have students complete the States of Matter Pre-Assessment to evaluate their prior knowledge and understanding of states of matter and changes from one state to another.

Activity Embedded Assessment:

During the activity, have students complete the States of Matter Data Sheet to demonstrate their involvement in and understanding of the activity.

Post-Assessment:

Have students complete the States of Matter Post-Assessment to assess their understanding of the activity and the knowledge they gained about states of matter and changes from one state to another.

Safety Issues

While the water is being heated, the metal pot is extremely hot so make sure students keep away from the stove to avoid burns. Have them remain close to the laptop where the temperature is being logged.

References

Copyright

Contributors

Supporting Program

Acknowledgements

This activity was developed by the Applying Mechatronics to Promote Science (AMPS) Program funded by National Science Foundation GK-12 grant no. 0741714. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.