Two Pieces: Luminescence & Smoke Alarms
Lothrop Craddock & CPSC.gov
Luminescence, by Lothrop Craddock
1 Most children are familiar with chemical luminescence. If you have ever played with glow sticks then you can remember that bright glow. This is chemical luminescence. As a child, glow sticks fascinated me. I would bend them all simultaneously to create the brightest glow possible. Afterwards, I would spend what seemed like hours reading under my blanket with these toys. It was always disappointing when the glow ceased.
2 Scientists consider chemical luminescence a cold light because there is little temperature increase. The light emitted is the result of two chemicals mixed together. As the chemical molecules combine, light is produced. In a glow stick, the two chemicals must remain separate until the consumer wants to create the glow. To accomplish this, one chemical is sealed inside a thin glass tube. It is inserted into a larger plastic tube that can bend easily. The space between the glass and plastic portions is filled with the second chemical. In this condition, glow sticks can remain stable for several years.
3 Glow sticks are common in amusement parks, novelty stores, and camping supply stores. Most glow sticks only work for a couple of hours. They contain low amounts of the chemicals needed to maintain a long glow. However, larger glow sticks can maintain their chemical reaction for 12 hours or more. This makes them perfect for night diving and evening strolls. The science of chemical luminescence even found its way into military use. Military-grade glow sticks have special light emissions that are only visible with infrared rays. From birthday parties to combat missions, glow sticks are extremely versatile.
Smoke Alarms, by CPSC.gov
Smoke alarms save lives. They can detect a fire early, and alert consumers, giving them valuable time to escape.
Despite that well-known fact, about two-thirds of fire deaths take place in homes with no smoke alarms or no working smoke alarms, e.g., smoke alarms with no batteries or dead batteries.
When shopping for smoke alarms, consumers should consider the different types of smoke alarms. Both types are effective smoke sensors. Ionization type detectors respond quickly to flaming fires. Photoelectric type detectors respond sooner to smoldering fires. Because both ionization and photoelectric smoke alarms are better at detecting distinctly different yet potentially fatal fires, and because homeowners cannot predict what type of fire might start in a home, CPSC staff recommends consumers install both ionization and photoelectric type smoke alarms in their homes. There are smoke alarms that combine both detection technologies into one unit called dual sensor smoke alarms.
In addition, consider interconnected smoke alarms. Interconnected smoke alarms allow all smoke alarms in the home to sound if one has detected smoke, and they may provide improved protection and offer more time to escape a fire.
Question
Imagine you are writing an essay on the science behind glow sticks and smoke detectors. Which sentences would be the most relevant to quote in your essay to support your points?
Put responses in the correct input to answer the question. Select a response, navigate to the desired input and insert the response. Responses can be selected and inserted using the space bar, enter key, left mouse button or touchpad. Responses can also be moved by dragging with a mouse.
Sentences Relevant to an Essay about Science Sentences Irrelevant to an Essay about Science
Sentences Relevant to an Essay about Science:
1. "Scientists consider chemical luminescence a cold light because there is little temperature increase."
2. "The light emitted is the result of two chemicals mixed together."
3. "Both ionization and photoelectric smoke alarms are better at detecting distinctly different yet potentially fatal fires."
Sentences Irrelevant to an Essay about Science:
1. "As a child, glow sticks fascinated me. I would bend them all simultaneously to create the brightest glow possible."
2. "In this condition, glow sticks can remain stable for several years."
3. "Most glow sticks only work for a couple of hours. They contain low amounts of the chemicals needed to maintain a long glow."