Independent Variables:

Colors (white, yellow, blue, red, and black)

Dependent Variables:

Temperature, power output, and number of infrared photons of each colored square

Experimental and Control Group:

The white construction paper is controlled because it represents the temperature of the surroundings. The other colors are the experimental group.

Hypothesis

If the color of an object is darker, it absorbs more radiant energy and reflects less light.

Question/Purpose

Data

The data shows that as the colors get darker from white to black, the temperature (C), power output (W), and number of photons per second all increase gradually.

Implications

I learned that the darker an object or material is, the more radiant energy is absorbed. I also learned how this affects everyday life. People wear darker clothing in winter in order to be warmer, while in summer many people light, bright colors. Another example is when architects are planning for a building, they have to consider the colors of the interior and the exterior because they do not want the building to be too hot or too cold.

Conclusion

In conclusion, I have determined that my hypothesis was correct. The darker an object is the more radiant energy it absorbs and the less light it reflects. Lighter colors absorb less and reflect more, while darker colors absorb more and reflect less.

**Absorption of Radiant Energy by Different Colors**

Procedures

Results

Experiment

**by**

Adetomilola Adedayo

01/15/15 -1A

Chemistry S/T

Adetomilola Adedayo

01/15/15 -1A

Chemistry S/T

How does the color of an object affect the amount of radiant energy that is absorbed?

The purpose of this experiment is to determine how different colors absorb and re-emit light and calculate the rate of energy flow.

Materials

Scissors

Ruler

Construction Paper (white,yellow,red,blue, black)

Infrared Thermometer

5 Styrofoam Plates

Cut out a 4-inch construction paper square of each of the following colors: white, yellow, blue, red, and black.

Place each square on one Styrofoam plate.

Place the squares in a location where they are in the sunlight, not touching each other.

Wait for several minutes so that the temperatures of the squares become stable.

Take the temperature of each square with the infrared thermometer, using Celsius, three times over a time period of about 1 minute. Record the data in a data table.

Average results for each square and record.

Now that you have the data, calculate the energy flow and the energy carried by the visible and infrared photons.

Answer the following questions:

What is the power output from the squares? Calculate the power that each square is producing, using Equation 2 from the Introduction.

Power equals energy (joules or electron volts) per unit time (seconds).

Use the temperature of the white paper as the "surrounding" temperature (s) in Equation 2.

Use the temperature of the colored or black square as "T" in Equation 2.

How many photons are being emitted by the heated squares? Calculate the number of infrared photons that are being emitted by the squares, assuming each photon has an energy of 0.000124 eV.

Convert joules to electron volts using this equation: 1 electron volt = 1.6 × 10-19 J

Then use this equation to find the number of photons: (x amount of J) × (1 eV/1.6 X 10-19 J) × (1 photon/0.000124 eV)

How many photons are being emitted by the heated squares? (Calculate the number of infrared photons that are being emitted by the squares, assuming each photon has an energy of 0.000124 eV.)

How does the power output and the number of photons that are emitted depend on the color?

Graph the temperature of each square, with color on the x-axis.

Graph the power output of each square. Since power depends on the fourth power of the temperature, a small difference in temperature can cause a big difference in power output.

Graph the number of photons emitted per second (use an energy of 0.000124 eV for each infrared photon).

This is not my exact experiment, just an example of how I did it.