Law of Conservation of Energy

Project title:  Law of Conservation of Energy

This virtual laboratory is intended for use in chemistry classes on the following topics:

  • 8th grade. Chapter VI. Introduction to Energy in Chemical Reactions.


  • Demonstrate the basic concepts of thermodynamics, such as energy, heat, work, the law of conservation of energy, and entropy.
  • Develop students ‘ skills of critical thinking and independent formulation of conclusions.

Practical part

  1. Upon starting the PhET “Energy Forms and Changes” simulation, you’ll find two modes available: Intro and Systems. Select Intro mode for exploring energy conversion during heating and cooling of various materials.

2. The screen displays the tools you’ll need for the experiment: two racks with heaters and coolers, two cubes (iron and brick), and two beakers, one filled with water and the other with olive oil. In the top-left corner, you’ll find a moveable thermometer for measuring temperature. The top-right corner features the Energy symbols and Link heaters buttons. Enable Energy symbols to see the energy icons (E). Enable Link heaters to control both heaters simultaneously

Before each experiment:

  • Reset the simulation: Find the reset button and click on it. This action returns the simulation to its initial state so you can start a new experiment with a clean slate.
  • Enable Energy symbols: Look for a button labeled “Energy symbols” and click on it. This will allow you to see the energy (E) icons that will be displayed during the experiment, showing you how energy moves and transforms.
  • Enable Link heaters: Find the button labeled “Link heaters” and click on it. This allows you to control both heaters at the same time, simplifying some experiments.
  • Check the thermometer: Place the thermometer next to the object you want to measure. Make sure the thermometer arrow is colored the same color as the object. This means the thermometer is set correctly and will show you the temperature of that object.

After each experiment: 

  • Write down the gained data in the table given below and make conclusions  

Virtual Experiment # 1

Place beakers of water and oil on the heating rack. Place a thermometer in each beaker. Slide the heater control to the “Heat” setting and hold. Once heated, move the heater control to the “Cool” setting. 

Virtual Experiment #2

Place iron and brick blocks on a rack with heaters. Attach a thermometer to each block. Turn on the heaters by moving the slider to the “Heat” indicator and hold it there. Once heated, move the slider to the “Cool” indicator. 

Virtual Experiment #3

Place the thermometer in each block. Heat the iron block for a few minutes. Then, place the hot iron on top of the brick to transfer heat to the brick.

 Virtual Experiment # 4

Place a beaker filled with water and another filled with oil on the heating rack. Then, place a cube of iron in the water and a brick in the oil. Install a thermometer on each object (4 in total). Move the heater’s slider up to the Heat indicator and hold. Then move the slider to the Cool indicator.

3. At the end of the experiment, fill in the table below:

Experiment NoDescribe or draw the observed changesConclusion




4. Please answer the questions below:

  • What happens to the temperature of iron and brick when heated?
  • How does the temperature of water and olive oil change when heated?
  • Why does iron heat up faster than brick?
  • Why does water heat up faster than olive oil?
  • What happens to energy when iron comes in contact with cold brick?
  • How does the law of conservation of energy manifest itself in this simulation?


The PhET simulation “Energy forms and changes” is an effective tool for studying the topics “Thermodynamics” and “Law of Conservation of Energy” in chemistry classes. It allows students to visually and interactively explore various examples of energy conversion, as well as independently formulate conclusions and use the knowledge gained to solve problems.

The use of simulation contributes to the development of critical thinking, information processing skills, and interest in studying the subject.