Hands-on activities are the key to teaching second graders about the scientific concepts of sound, light and heat. Providing students with opportunities to explore these elements of energy through simple experiments will make their discoveries more meaningful.

Write the words "Sound," "Light" and "Heat" on the board. Explain to the class that over the next several days they will be learning about each of these terms. Brainstorm with the class and write words under each of the terms that the students feel relate to that term. This will be a useful reference as the lessons continue.

Give students several opportunities to experience sound in their learning environment. Begin by having them brainstorm objects in the classroom and the sounds that they make. Tell the students that sound is created by the vibrations of an object. Introduce the vocabulary word "pitch" (the highness and lowness of sound). Explain that the pitch is directly affected by the amount of vibration allowed by an object. Have the students add this term and its correct definition to their science journals.

Set up three glass bottles and fill each with a differing amount of water. Add a drop of food coloring to each bottle so that they can be distinguished one from another. Ask one student to use a metal spoon to tap the side of each bottle, allowing time in between taps so that the rest of the class can hear the distinct sound that it makes. After discussing the different sounds, have students record their ideas in their science journals. Ask the students which bottle made the highest pitch and which one made the lowest. Next, have another student volunteer to tap the bottles again. This time use a wooden spoon. Again ask the students to record their findings in their journals. Now ask the students if the material that the spoon is made out of made any difference. Have the students make predictions about what would happen if the water amounts were changed. Remind them that the pitch is affected by the amount of vibration that is allowed and ask them to think about how more or less water in the bottle would make the pitch change.

Instruct the students to cut out a shape from an ordinary piece of paper. Turn off the lights in the classroom. Ask the students to come to the front of the class in pairs. Give one student a flashlight and tell the other student to stand near the board and hold the paper cut-out in the beam of the light to create a shadow on the board. After each student has had a chance to experience making a "shadow puppet," discuss with the class how the shadows are formed.

Give the students small cards with the words "opaque," "transparent" and "translucent" printed on them. Ask the students to glue the cards into their journals -- one word per page. Explain to the class that opaque materials do not allow light to shine through them. Tell them that transparent materials allow light to shine through easily and that translucent materials allow some light to shine through.

Divide the students into small groups and give each group a flashlight, pieces of cardboard, some waxed paper and plastic wrap. Ask them to take turns shining the light through each of the objects and then place the object on the page in their journal that matches it with the correct term. After each group is finished, bring the class back together and have the groups share their findings. Make any corrections that need to be made and then instruct the students to glue the objects into their journals.

Send the students on a scavenger hunt around the classroom to find other objects that can be described as opaque, translucent or transparent. Students can create a collage of their findings by drawing pictures of the objects and pasting them on poster board to be displayed for future reference to these scientific terms.

Ask the students to choose a partner for charades. Have one partner act out using an object that is hot and the other partner to act out using an object that is cold. While monitoring the progress of each pair, ask guided questions like, "Is your object always hot or cold?" and, "What causes your object to be hot or cold?" Have the pairs discuss the differences and record their ideas in their science journals by drawing pictures to illustrate what they have discovered through this introductory activity.

Write the words "conductor" and "insulator" on the board. Ask the students if they know what these words mean. Tell them that a conductor is a material that allows heat to travel through it easily and an insulator is something that does not allow heat to travel through it easily. Set up a large bowl of hot water and have one student at a time come up to place spoons made out of different materials into the water to test whether these materials are insulators or conductors. Use a metal spoon first. Dip it into the water for a few seconds and then let the student carefully touch the end of the spoon to feel the temperature of the metal. Ask the student to describe what he is feeling and explain why he thinks that material is a conductor or an insulator. Repeat these steps using a plastic spoon and then a wooden spoon. Have the students record their findings in their journals after the class has correctly identified each of the conductors and insulators.