Creating Your Own Sunset

Sherrie Seidensticker, Jeffers Pond Elementary, Prior Lake Minnesota, adapted from the web page scifun.chem.wis.edu/HomeExpts/BlueSky.html

Summary

In this activity, students will observe a physical example of how the sunrises and sunsets show color in the sky. Students will write their observations during the demonstration and during their guided inquiry practice time.

Learning Goals

1. Through the process of this activity, students will understand and be able to communicate the activity of observation.
2. Students will begin their basic understanding of how the sky changes colors.
3. Also students will learn the process of following directions through guided discovery.

Context for Use

1. I plan on using this activity with 2nd graders but it could be used with all grades.
2. My class size will be 25 students.
3. I will be trying this activity in a regular classroom that has carpet floors and individual desks.
4. This activity will take about 45 minutes. I will first demonstrate the activity with time for students to do some group observations. Once I have modeled the activity and we have talked about the student's ideas, they will go to their own areas and do the same activity in groups of three.

Description and Teaching Materials

Materials Needed – Clean glass jar, water, milk, flashlight, 1 cup measuring cup, ¼ cup measuring cup.

1. Fill the glass container ¾ full with water. Place the flashlight close to the jar and talk about what you notice.
(You maybe able to notice some particles of dust floating in the water. Can you see the beam of light through the water? Look from the top and sides and talk about what you are observing.)
2. Add ¼ cup of milk to the jar and stir. Place the flashlight close to the jar on the side first. What do you notice? (Notice the beam of light, you can see more clearly where the light is as it passes through the water. Hold the light on top of the jar, what do you see?)
3. Add another ¼ cup and continue the observation as in step 2.
4. Add the rest of the milk to the water and stir. Now the beam of light looks even bluer from the sides and more yellow from the end.
5. Some questions to ask:
a. What causes the beam of light from the flashlight to look blue from the side and orange when viewed head on?
(Answer- Light usually travels in straight lines, unless it encounters the edges of some material. When the beam of a flashlight travels through the air, we cannot see the beam from side to side because the air is uniform and the light from the flashlight travels in a straight line. However, if there should be some dust in the air or water, then we catch a glimpse of the beam where the light is scattered by the edges of the dust particles.

When milk is added to the water, you add many particles to the water. Milk contains tiny particles of protein and fat that is suspended in the water. These particles help spread the light by different amounts.

As with sunsets or sunrises, the light we see in the sky is sunlight that is scattered by tiny particles of dust in the atmosphere.

Teaching Notes and Tips

It is important that when you do this activity, you have a large enough container to pour the water and milk into to allow the light to be visible for all students to see.
Also this activity is very affective if it can be done in the dark.
I have only done this activity in my kitchen with my own children. They thought it was exciting to see the colors. It was easier to see the color changes when we went into a completely dark room.

Assessment

This activity will be the first for my 2nd graders to practice how to make observations during an activity. I will be putting key words on the board such as observation, light beam, transparent, and particles. Each student will first take part in the class observation as a whole group. We will talk about what they notice during the activity. Once the students are done with the activity, I will ask them to draw a picture or write out what they observed during the activity. I will be looking for students to identify at least once observation in their reflection.

Standards

2.1.1.1.1 – Understand that when a science investigation is done the way it was done before, even in a different place, a very similar result is expected.
2.1.2.1.1 – Use observation to develop an accurate description of a natural phenomenon and compare one's observations and descriptions with those of others.

References and Resources