CONTENT STANDARD: Physical Science GRADE: Sixth GOAL: 6500 To understand the significance of change in the physical world CONTENT TOPIC: Transformation of Energy CONCEPT: The sun's energy arrives as light with a range of wavelengths, consisting mainly of visible light with significant amounts of infrared and ultraviolet radiation. PERFORMANCE OBJECTIVE: 6ELE6.00 ???????? INSTRUCTIONAL OBJECTIVES: The learner will:

6.01 Define light.
6.02 Use the characteristics of light to explain different phenomenon.
6.03 The learner will become familiar with electromagnetic spectrum and selected forms of invisible rays.

I. Definition
II. Characteristics of light

TN COMPONENT OF SCIENCE: Process of Science TN GOAL:

To enable students to demonstrate the processes of science by posing questions and investigating phenomena through language, methods, and instruments of science.

1.5 EXPLAINING - Phenomena and related information are made understandable through discussion that culminates in a higher level of learning.

1.5a Interpret the meaning and significance of data presented in tables and graphs.

BENCHMARK The graphic display of numbers may help to show patterns such as trends, varying rates of change, gaps, or clusters.

MATERIALS:

Prism, radiometer, spectroscope of diffraction grating, clear light bulb, white paper, pencil, thumbtack, marking pens, scissors



Lesson One

Name a form of energy that we have studied. Today we are going to study what makes up light and how it relates to your life.

1. Definition

Light is a form of energy that you can see and is always moving.

2. Behavior or characteristics

A. Light travels from the sun to earth by electromagnetic waves.

B. Wavelength can be described in 2 ways: The distance between the crest of one wave and the crest of the next; or the distance from one trough to the next.

C. Frequency is the number of waves that pass by at a point each second. Different light waves have different frequencies. The shorter the wavelength of a wave, the greater its frequency.

D. Intensity is the brightness of light. It depends on the amount of light from the source. For example, a 60-watt bulb produces more light than a 25-watt bulb. It depends on the distance from the light source. As light travels away from the source, it spreads out over a larger area. As a result, the intensity of light decreases as the distance from a source increases.

The sun is a major source of energy for changes on the Earth's surface. The sun's energy arrives as light with a range of wavelengths, consisting mainly of visible light with significant amounts of infrared (heat) and ultraviolet radiation. Visible light is also called white light. White light can be separated into colors by passing it through a prism. A prism is a triangular piece of glass, quartz or plastic that separates white light into a band of colors (spectrum) by bending it.

(Do one or all.)

1. Hold the radiometer in the sunlight to demonstrate how light is a form of radiant energy.

2. Investigating the color of light. Using a spectroscope or diffraction grating, look at an incandescent bulb. Then, look at a florescent light. (Ask students to tell how they are alike and how they are different.) Next, hold a clear bulb (3 or 4 in.) away and use the diffraction grating to observe the light again. (Tell the students to describe what they see.)

Tell each other what makes up light. State. Using the characteristics of light: Explain why rainbows form. Answer (Rainbows form because water droplets in the air act like prisms bending light rays and separating white light in colors.)

How did the radiometer prove that light is a form of radiant energy?

Lesson Two

To become familiar with the electromagnetic spectrum and selected forms of radiant energy.

Two aluminum cans ( One painted black) K, two thermometers, graduated cylinder, tap water per group

In the last lesson we learned that light travels from the sun to earth by (response) waves. (electromagnetic) Today we are going to become familiar with the electromagnetic spectrum and selected forms of invisible energy.

Our sun provides many forms of energy besides light, which we can feel. These energy forms are radio rays, infrared rays (heat), ultraviolet rays, X-rays, and gamma rays. There is empty space between the earth and the sun. Since convection cannot take place without a fluid (gas or liquid), the sun's energy must travel in waves. Heat waves are invisible and are called infrared.

The entire system of all waves is the electromagnetic spectrum. Spectrum means band. You observe waves when you throw a rock in still water. The waves move (radiate) out and away. Energy works in the same way. Radiation simply means the sending out of energy waves. A light bulb radiates light. A radio station radiates radio waves. A boiling pot of water radiates heat. An X-ray source radiates X-rays.

(Starting with the longest wave- the radio wave- make a chart showing the electromagnetic spectrum on the board. Radio wave, microwave, infrared wave, visible light, ultraviolet wave, X-ray, and gamma ray.)

1. Place 70 ml of water into each can. Using the thermometer check the starting temperature of water in both cans every 5 minutes.(These materials will be the same for each group.)

( Ask students to predict which will be the same for each group.)

Could these models represent houses?

unpainted can	time min.	0	5	10	15	20	25	30	35
	temperature
	time min.
black can	temperature	0	5	10	15	20	25	30	35

Subtract the temperature at the beginning from the temperature at the end of 35 minutes. How many degrees did each have?

2. Graph the temp. changes of each can by placing time on the horizontal axis and temp. on the vertical axis. Graph each set of data on the graph using 2 different colors. Draw each curve.

From the data you collected, which color roof will be best to reflect the energy of the sun? Explain.

Which color roof would absorb the most energy? Explain.

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