A STUDENT SHOULD KNOW THAT:

A. HEAT AND LIGHT COME FROM A VARIETY OF SOURCES.

1. The sun is the primary source of heat and light on earth.
2. Things that give off light, also give off heat.
3. Sources of heat: burning, rubbing or mixing one substance with another, sunlight, fire, light bulb.
4. Sources of light: sun, light bulb, stars, lightning bugs/fireflies, flames.

B. HEAT CAN BE TRANSFERRED FROM ONE PLACE TO ANOTHER.

1. Heat moves from a warmer object to a cooler object until both reach the same temperature.
2. Heat moves through some materials more easily than others.
3. A warmer object can warm a cooler object by direct contact or from a distance.

C. LIGHT BEHAVES DIFFERENTLY WHEN IT STRIKES DIFFERENT OBJECTS.

1. When light strikes a surface, the light may pass through the material, it may be absorbed, and/or it may change direction.
2. When light strikes a transparent material, such as glass, almost all of the light passes through it. We can see clearly through transparent materials.
3. When light strikes a translucent material, such as waxed paper, only some of the light passes through it.  The light changes direction and is scattered. We cannot see clearly through translucent materials.
4. When light strikes an opaque material, such as wood, none of the light passes through it. Some light is reflected and some light is absorbed. We cannot see through opaque materials.
5. Materials absorb some of the light that strikes them. Substances like clear glass absorb very little light.

D. SOUND IS PRODUCED WHEN AN OBJECT VIBRATES.

E. THE PITCH OF A SOUND DEPENDS ON THE RATE OF VIBRATION.

1. The faster the vibration of the object, the higher the pitch.
2. The slower the vibration of the object, the lower the pitch.

F. ELECTRICITY CAN BE USED TO PRODUCE HEAT, LIGHT, AND SOUND.

1. Electrical current flows from the source of electricity along one path to the appliance (i.e., light bulb, bell), passes through the appliance and then returns through a second path to the source.
2. Electricity flowing in a wire may cause the wire to become warm and glow. For example, the filament in an incandescent light bulb, the heating filament in a toaster, and the coil in an electric heater.

A STUDENT SHOULD BE ABLE TO:

• Identify from observations that there are sources of heat and/or light.
• Infer from observations that heat can be transferred from one place to another.
• Recognize, using observations, that light behaves differently when it strikes different objects, such as those that are smooth, shiny, rough, opaque, and/or transparent.
• Infer from observations that sound can be produced by vibrating objects.
• Recognize from observations and data that are collected, recorded, and analyzed, the cause and effect relationship between the rate of vibration and pitch.
• Generalize from observations that electricity can be used to produce heat, light, and sound.