Is It Hot Enough for You Yet?

The sun is the principal source of energy for the earth.

Sun and thermometer

Inquiry Skills Used

Initiating & Planning: questioning

Performing & Recording: organizing data on a chart

Analysing and Interpreting: drawing conclusions based on information gathered

Communicating: oral communication

Safety Considerations

Students should be reminded about safe practises regarding handling glass and reminded to pick up any broken glass. In the event that the glass jars sit in the sun too long, the students should be cautioned that the jars may become quite hot. They should also be reminded not to pickup any broken glass, but to report broken glass to the teacher immediately.


Most children know that when they sit in the sun, it is warmer than sitting in the shade.   They do not always grasp the concept that the sun is a source of energy.  The students will explore how the sun’s energy can create heat.

What You Need

  • Baby food jars with lids
  • Lamp with incandescent light bulb
  • Water at air temperature
  • Chart to write the results
  • Thermometer (optional)


What to Do

  1. Brainstorm with the class, asking why the weather becomes hot.
  2. Explore areas in the class and outside that are hotter than others.
  3. Ask the students for their ideas on why some areas are hotter than others.
  4. Divide the class into groups.
  5. Give each group a sealed jar with some water in it.
  6. Ask the class to try to warm the water up without using a stove. They can place their jars anywhere outside or in the room, either in the shade or in the direct sunlight.  The teacher should place one jar in a cupboard.
  7. After one hour, each group should bring their bottle back into the class.
  8. Using the students’ sense of touch, ask them to assess whose bottle is hotter.
  9. Brainstorm with the class, the causes for the increase in the temperature of the water in the jar.


Where to Go from Here?

Hopefully, one of the groups placed a jar under the lamp with the incandescent light or this could be a separate lesson with the teacher placing the jar under the light. Ask the students where the energy came from to heat the water. This could lead into a discussion about solar energy.

STSE Links

Raise the issue of solar heating and its use in this experiment. Have the students speculate how they could heat their house using this type of technology.

Cross Curricular Connections


  • Write a report about how we can create heat in the future.


  • To enhance this activity, the following book can be read to the class as a teacher-directed reading activity: Earth Dance by Joanna Ryder. This book is available online from The Magic Suitcase at the following site: .



  • Measure the temperature of the water or recognize that there are changes in temperature caused by the sun.
  • The results of the heat could introduce the terms greater than or less than.

Visual Arts

  • Draw a picture of the experiment.

Grade 1: Matter and Energy

Contributed by: Gordon Webb