Tuesday, March 3, 2015

Framing Our Reading - Part 3 - Extending Thinking

ED 620 Module 5 

Article: Why metals have a blast in water

Text Citation or Link
Rationale for Choosing
Text Frame(s)
Strategies Used and Resource
Engagement Example
Appropriate for scientific informational text. The strategy forces students to think about what they have read through asking themselves questions from the text. Promotes research because students must find a second source to corroborate the answers to their questions from the original text. Gives students practice with writing and summarizing. Springboard for PowerPoint presentation summarizing the topic.
Cause/Effect

Compare/Contrast
Questions Into Paragraphs (QuIP) (McLaughlin, p. 93-95)

My teammate, Amanda, chose the article this week. The article, “Why Metals Have a Blast in Water,” (Ornes, 2015) is a great article for secondary students to read because students like excitement. The article describes and seeks to explain one of the most exciting experiments that teachers can use to ignite student interest in chemistry, because of the explosive nature of the reaction between alkali metals and water. The teacher could easily assign the article as reading after doing a live, in-class demonstration of the experiment referenced in the article. Or the teacher could assign the reading as homework the day before doing the live experiment in class and then have the students read the article again using the extending thinking strategy in class. Either way, the article has lots of possibilities for sparking learning in the classroom. After doing the demonstration and the reading strategy exercise, the teacher could easily assess the students with a three- to five-slide PowerPoint or Prezi presentation. At that point, the presentation should prove easy for the students to create since they will have spent a couple of days getting familiar with the material. The summary paragraph at the end would help them process and organize their thoughts. The topic lends itself to using great visuals, such as images and videos in their presentation. For all of these reasons, the article is an excellent choice to use to model an extended reading strategy with secondary students.

It appears that there are fewer extended reading strategies than the other types of strategies. The rationale for choosing the Questions Into Paragraphs (QuIP) extending reading strategy is that it is one of the few extended reading strategies that are appropriate for scientific informational text. The strategy forces students to think about what they have read by asking themselves questions that can be answered from reading the text. In addition, they must do research and find a second source to compare the answers to their questions from the original text. Lastly, students must combine information found from both sources to confirm their findings and summarize the major points from both texts.

I used a close reading strategy while reading the original article. I quickly and thoroughly read through the article at first. I then re-read the article a second time, making annotations in the margins, signaling ideas that I knew, thought were interesting or that I did not know. I found that while doing so, I also needed to draw illustrations of what the authors described in the article, because of the complex nature of the chemical reactions. (Probably the best extending reading strategy to use for this particular article is the ‘Sketch to Stretch’ strategy, but my teammate, Amanda, had already chosen that strategy.) All of this helped when I reached the end of the article and I needed to use the Questions Into Paragraphs extending reading strategy.

One of the best features about the QuIP strategy is the requirement that the reader selects a second article for comparison. In my case, I chose the second article, “Why Sodium and Potassium Really Explode in Water” from the Chemical & Engineering News online magazine. (Jacoby, 2015) This second article answered a lot of my remaining questions that the first article did not answer or did not explain as clearly.

The text frames for the QuIP extending reading strategy are cause/effect and compare/contrast. Because the strategy requires the reader to ask himself questions about what he read, the reader must determine the relationship between what causes the events mentioned in the text and the effects of those events in the text. This process promotes higher-level critical thinking. Also, by forcing the reader to read from two different sources about the same topic and summarize at the end, the strategy influences the reader to compare and contrast the various points the authors of both texts make. In formulating these comparisons, the reader must familiarize himself with the text even more and again use critical thinking skills. Finally, the part of the strategy where the student takes the major points from the texts and builds them into a summary paragraph for the conclusion supports a solid understanding of the reading.
                                                                                                                             
QuIP – Questions Into Paragraphs
Question
Source A
“Why metals have a blast in water” - Science News for Students (Ornes, 2015) https://student.societyforscience.org/article/why-metals-have-blast-water?mode=topic&context=6
Source B
“Why Sodium and Potassium Really Explode in Water” – Chemical & Engineering News (Jacoby, 2015) http://cen.acs.org/articles/93/web/2015/01/Sodium-Potassium-Really-Explode-Water.html
What causes metals to explode when they interact with water? (original textbook answer)
When water hits the metal, the metal releases electrons which generate heat when they leave the metal. In the process, the electrons break apart the water molecule releasing hydrogen atoms, which are explosive. The presence of heat causes the loud eruption.
Science used to think that tossing a piece of an alkali metal in water causes an explosion because the metal dissolves, generating an extreme amount of heat and transferring electrons to the water. The dissolution step also generates steam and forms hydroxide ions and hydrogen, which can be ignited, making the process even more energetic.
Do all metals explode in the presence of water?
Only elements that are alkali metals and have a +1 charge provide such an explosive reaction in the presence of water.
Science enthusiasts have long marveled over the famously energetic way sodium and potassium explode on contact with water. (alludes to the fact that not all metals react this way)
What is the new theory that chemists use to explain why metals interact with water so explosively?
When the water hits the metal, it releases electrons. After the electrons flee, positively charges atom remain behind. Because like charges repel, the positive atoms push away from each other, creating metal spikes. The process exposes new electrons to the water. These electrons are from atoms inside the metal. When the electrons escape from the atoms, they leave behind more positively charged atoms and cause more spikes. The process continues until enough heat builds up to ignite the hydrogen.
Within a fraction of a millisecond of making contact with water, the Na/K droplets form numerous spikes that protrude into the water. Molecular dynamics analysis indicated that nearly instantaneous transfer of electrons from the spikes to the water rapidly generates positively charged alkali ions, which vigorously repel and cause a so-called Coulomb explosion. It is the speedy manner in which that process propagates and generates reactive metal surfaces that triggers the overall explosion.
The researchers have figured out many of the key aspects that enable this highly exothermic reaction to become explosive, rather than self-quench.
What led chemists to question the old textbook explanation of why metals interact with water?
Chemist Philip Mason did not think the old textbook explanation covered the whole story. He thought that the steam that the electron heat created should have acted like a blanket over the electrons, preventing the hydrogen blast, instead of causing a large explosion like it did.
Some researchers have puzzled over how the process can occur so quickly. They recognized that the steam and hydrogen generated early on in the reaction should form a buffer layer over the metal surface and impede water from continuing to react.
What tools did the scientists use to find their new theory?
Scientists set up a reaction with a lithium/ mixture and used a high-speed camera to observe what actually happens in the reaction.
Chemists studied the process with ultrafast photography and computational techniques. A number of factors, including sample surface cleanliness and temperature, can prevent chunks of alkali metals from exploding on contact with water. The team eliminated those variables and others by using a sodium-potassium alloy that remains liquid at room temperature and a droplet delivery system featuring a calibrated syringe.

Summary: Scientists used to think that the reason why alkali metals like sodium and potassium caused a big explosion when they interacted with water was because the metals dissolved in the water, leading to the emission of heat. The buildup of heat fueled the explosion. However, a team of chemists’ insights caused them to question this long-standing explanation. Pavel Jungwirth and Philip Mason believed that if that were truly happening, the steam from the water would create a blanket effect and dampen or prevent the explosion altogether. To look more closely into the reaction at the subatomic level, Jungwirth and his team used high-speed cameras in a set up to monitor the reaction of a drop of a sodium/potassium mixture, which is liquid at room temperature, and water. What they found is that the metal forms spikes immediately prior to the reaction. When the water comes in contact with these spikes, it releases electrons. Upon the electrons’ departure, positively charged atoms stay behind. Since like charges repel, the positive atoms push away from each other creating spikes. As the process repeats itself and more spikes form, enough heat builds up to ignite the hydrogen, before the steam can suppress the explosion. The scientific process that Jungwirth’s team of chemists used to investigate their inquiries proves that one should never stop questioning and thus never stop learning.


In her book, Maureen McLaughlin describes the QuIP strategy as a tiered approach in the classroom: explain, demonstrate, guide, practice, and reflect. She suggests that the teacher emphasize with the students the importance of summarizing after reading to extend thinking about the text. Then she recommends explaining QuIP as a format for questioning, researching, and summarizing that centers on creating three questions and responding to those questions from two distinct sources. (McLaughlin, 2015) Following this, the teacher will show the students how the process works by sharing the graphic organizer with them and modeling the procedure for generating higher-level questions. Upon completing their graphic organizers, the students will pair up and work together while the teacher guides them to create two additional questions. The students will then work independently to draft their summary paragraphs, which gives them practice with technical writing. Finally, the teacher will encourage the students to reflect on how the QuIP extending reading strategy helped them to gain a more solid understanding of the texts and how they could apply the same strategy in other ways. (McLaughlin, 2015)

References

Buehl, D. (2014). Classroom Strategies for Interactive Learning (4th ed.). Newark, DE: International Reading Association.
Jacoby, M. (2015, January 17). Why Sodium And Potassium Really Explode In Water. Retrieved from Chemical & Engineering News: http://cen.acs.org/articles/93/web/2015/01/Sodium-Potassium-Really-Explode-Water.html
McLaughlin, M. (2015). Content Area Reading: Teaching and Learning for College and Career Readiness. Upper Saddle River: Pearson.
Ornes, S. (2015, February 18). Why metals have a blast in water. Retrieved from Society for Science & the Public - Student Science: https://student.societyforscience.org/article/why-metals-have-blast-water?mode=topic&context=6
San Bernadino City Unified School District. (2014, September 16). Close Reading of Informational Science Text. Retrieved from YouTube: http://www.youtube.com/watch?v=o_7MY8khBag
                                                                                                                                       
My teammate Amanda Slonaker read the same article using the "Sketch to Stretch" Technique. http://amandasteachingjourney.blogspot.com/. While my other teammate, Christine Betley, read the same article using the "Magnet Summaries" strategy. http://chesapeaceful.com/


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