Experiment_no__20.docx

Name: _______________________________________ Date Started: __________________ Grade and Section: _____________________________ Date Finished: _________________ Name of Teacher: ______________________________ Group No.: ____________________

Experiment No. 20 Blackbody Spectrum (Structured/Virtual) I.

Introduction

Drawing (2 pts) Procedure (3 pts) Data and Results (4 pts) Conclusion (3 pts) Application (2 pts) Neatness (1 pt) TOTAL

A star is a large ball of hot gas like the Sun. Its diameter is about thousands to millions of kilometers. It emits large amounts of radiant energy from nuclear reactions in its interior. It is because of this radiant energy they emit that they look like points of lights in the sky at night. They appear as a steady point of colored light when seen outside of the Earth’s atmosphere but as you look at it within the Earth’s atmosphere, it is a point twinkling light. II. Problem What does a star’s color tell about its temperature? III. Materials Simulation IV. Drawing

V.

Procedure

1. Light the candle. 2. Wait until the flame is tall and steady. Observe the flame. Notice the layers from the inside out. 3. Heat the end of the wire at the outer part of the flame. Observe the color of the wire. 4. Place it at the middle part, then at the inner part. Note the color each time. 5. Check the link at the end page of this experiment. Do the simulation of the black body spectrum by putting the intensity level to 100. Answer the guide questions provided. VI. Data and Results

VII. Guide Questions 1. Describe the color of the different temperature. a. 1515 K ____________________________________________________ b. 3540 K ____________________________________________________ c. 9075 K ____________________________________________________ 2. Which temperature is a. Hottest ____________________________________________________ b. Coldest ____________________________________________________ c. Least hot ____________________________________________________ 3. Which color has the highest temperature? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ 4. Which color has the lowest temperature? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ 5. Our Sun is a yellow star. What can you say about its surface temperature? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ 6. What happens to the blackbody spectrum as you decrease the temperature? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ VIII. Conclusion _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ IX.

Application

What do you think will happen if the Sun, the nearest star to Earth, dies? Expound your answer. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________

Reference: https://phet.colorado.edu/sims/blackbody-spectrum/blackbody-spectrum_en.html