TIC TAC LESSON Heat and Light Copyright © 2002 Glenna R. Shaw and FTC Publishing All Rights Reserved Welcome to TicTac Town Second Grade

Heat and Light Heat and light are both types of energy. We can see light energy. We feel heat energy. Some light energy comes from the sun. When sunlight strikes the earth, it changes to heat. Without the sun the Earth would be cold and dark.

Making Heat and Light The sun is not the only thing that gives us heat and light. Fire also gives us heat and light. Some people use fire for heat, and some people use fire for light.

Light Without Heat A few things give off light without giving off heat. A lightning bug is a good example of this.

Heat Without Light Some things may not look hot. We cannot see heat. You should not touch things that might be hot.

Reflecting Light Many things do not give off their own light (rocks, trees, water.) We need light to help us see these things. We can see things that do not give off their own light. We can see them because they reflect light. Light bounces off things that reflect light.

Good Reflectors Some things reflect light better than other things. Light colors reflect light better than dark colors. Smooth, shiny things reflect much light. A mirror is smooth and reflects light well.

Good Reflectors Not all light that shines on objects is reflected. Light passes through some things. Some things let only part of the light pass through. Some things do not let any light pass through.

Heat Moves Heat moves through things. We can feel heat from a fire. The heat moves through the air. When food is cooked, heat moves up through the pan to the food.

Heat Moves Sometimes we do not want heat to move through things. Heavy clothing, thermos bottles, and insulation are all examples of things that keep heat from moving.

Changing Heat Energy Things with lots of heat energy are warm. Rubbing your hands together makes them warmer. You are adding heat energy.

Measuring Hot and Cold We can use a thermometer to measure hot and cold.

Using Heat We use heat energy to change things. Food changes when we cook it. Heat keeps our homes warm. We use heat to dry our clothes.

Using Light We use light to light our homes. We use it to light our streets also.