Example

Dress Rehearsal

Your teacher has asked you to answer the following question: How do objects get their color? Yikes! It’s a mystery, you think. You must use your textbook to explain and describe how this process works in order to answer the question and, going even further, explain your answer. 

Color. Color. Hmmm. You’ve already learned that Isaac Newton used a prism and a beam of sunlight to show that sunlight is composed of all the colors of the rainbow. But that’s about ALL you remember. You turn to your textbook for further explanation. It notes that Newton’s shenanigans resulted in a spread of colors, red, orange, yellow, green, blue, and violet. This is known as a spectrum. Sunlight itself is white light. 

Under white light, white objects appear white, and colored objects have their individual colors, your textbook explains. Newton proved with his prism that colors of objects are not produced by the objects themselves. They are made by the absorption or reflection of white light, which contains all the colors of the rainbow. Your pot o’ gold is in the rest of the explanation.

You know that the color of an object is created because it reflects light. Your textbook makes this concept clear by describing the electrons within atoms and molecules that orbit nuclei, sending out waves of energy. Furthermore, different objects have natural frequencies that absorb and emit radiation. These, in turn, determine whether light is absorbed or reflected. Most objects absorb the light of some frequencies but may reflect the rest. You’re cool with that.

The color of an object is determined by the amount of absorption of some frequencies and the amount of the reflection of the rest. A red object absorbs most frequencies and reflects red. A white object reflects all frequencies since white is a combination of all colors. The text clarifies that black is not a color, but an absence of light. WHO KNEW? Black objects that you can see are visible because they do not absorb all light that is on them.

With that information bursting in your brain, you are asked to use the text to explain how color is produced by the reflection of light. You read the information from your textbook, and, with your elbow partner, list the key details in the process. You might bullet your information, draw pictures, or write in paragraph form. Colors of objects are created by the way the objects reflect light. Electrons within atoms and molecules whirl around the nuclei, often being forced into larger orbits due to vibrations of electromagnetic waves, such as light. 

You and your partner conclude that different materials have natural frequencies for absorbing light. Light might be reemitted as in the case of a transparent object when light passes through the object. BUT…wait for it, wait for it...in the case of an opaque object, it becomes a reflection. You also note that most objects absorb the light of some frequencies and reflect the remainder. If an object absorbs most of visible frequencies and reflects red, the object appears red. If the object reflects the light of all visible frequencies, it is the same color as the light that shines on it. If a material absorbs all the light that shines on it, the object reflects no colors and appears black. WHEW!

By citing specific details of how objects absorb and reflect light, you’ve explained how objects get their color. ***Applause here***

Source: 

Hewitt, Paul G. Conceptual Physic, 3rd edition. California: Addison-Wesley Publishing Company, 1997.

Drill

Read the passage on condensation, and then identify the text evidence that supports each of the conclusions that follow.

Condensation is the process by which water vapor in the air is changed into liquid water. Condensation is crucial to the water cycle because it is responsible for the formation of clouds. These clouds may produce precipitation, which is the primary route for water to return to the Earth's surface within the water cycle. Condensation is the opposite of evaporation.

You don't have to look at something as far away as a cloud to notice condensation, though. Condensation is responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and for the water on the inside of the windows in your home on a cold day.

The phase change that accompanies water as it moves between its vapor, liquid, and solid form happens because of differences in the arrangement of water molecules. Water molecules in the vapor form are arranged more randomly than in liquid water. As condensation occurs and liquid water forms from the vapor, the water molecules become more organized and heat is released into the atmosphere as a result.

Source:
“The Water Cycle: Condensation.” U.S. Geological Survey. 3 March 2012. U.S. Department of the Interior. 21 April 2012. http://ga.water.usgs.gov/edu/watercyclecondensation.html

Conclusions:

1. Without the process of condensation, we would never experience cloudy days.
2. Evaporation is the process by which liquid water is changed to water vapor.
3. As evaporation occurs, water molecules become less organized.
4. Solid water or ice contains the most organized water molecules.
5. Condensation occurs as water vapor cools.

Text Evidence/Explanations:

1. “Condensation is crucial to the water cycle because it is responsible for the formation of clouds.” If condensation is responsible for the formation of clouds, then without it, clouds would never form. 

2. “Condensation is the process by which water vapor in the air is changed into liquid water. [ ... ] Condensation is the opposite of evaporation.” Evaporation isn’t defined in this passage, but the definition of condensation and the information that condensation is the opposite of evaporation give us enough info to infer or figure out the definition without being told. Good readers can use text evidence to make inferences or predictions about things that aren’t directly stated. 

3. “As condensation occurs and liquid water forms from the vapor, the water molecules become more organized.” Again, evaporation isn’t discussed here, but if we know it’s the opposite of condensation, we can use this information to make another inference. 

4. “Water molecules in the vapor form are arranged more randomly than in liquid water.” If water molecules in vapor are random and become more organized in liquid form, then we can conclude that the molecules would become even more organized as water moves into solid form. 

5. “Condensation is responsible for ground-level fog, for your glasses fogging up when you go from a cold room to the outdoors on a hot, humid day, for the water that drips off the outside of your glass of iced tea, and for the water on the inside of the windows in your home on a cold day.” All of these examples show that condensation occurs when water vapor in the air comes into contact with a cold surface. The warm air outside condenses when it touches the cool surface of your glasses or the surface of your cold drink.