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Day 67: Radioactive Polonium-210, not Thallium November 26, 2006

Posted by Admin in Astronomy, Chemistry, Science in the News.

Today was Day 1 of our new unit on Astronomy. We began by completing the first two columns of a KWL, followed by a discussion about the meaning of “Astronomy.” After reviewing the chemistry test grades, we then discussed the current investigation regarding the Russian ex-spy case.

Last week, the specific cause of the illness suffered by a former Russian spy was still being investigated. Since then, the story has deepened significantly, first with the victim’s death this past weekend, followed by reports that radioactive Polonium-210 was the likely culprit.

Hat tip: Ancora Imparo:

There are several ways for radioactive decay to occur. Polonium-210 undergoes alpha decay, emitting an alpha particle (two protons and two neutrons, essentially a helium-4 nucleus). As a result, 82 protons (and 124 neutrons) are left. This is lead-206, which is stable. Alpha particles are quite massive, so they cannot penetrate solid matter very well. Therefore, polonium-210 must be inside someone’s body to inflict much damage—so it must be ingested, inhaled, or administered through a wound, according to Roger Cox, director of the UK’s Centre for Radiation, Chemical and Environmental Hazards. Mr. Cox believes that Mr. Litvinenko would have to ingest the polonium to account for the large amount found.

Additionally, Polonium-210 has a much longer half-life than Thallium, which should make it easier to trace, according to Deborah MacKenzie at the New Scientist (read the full article here):

“To poison someone, large amounts of polonium-210 are required and this would have to be manmade, perhaps from a particle accelerator or a nuclear reactor,” said Dudley Goodhead at the UK’s MRC Radiation and Genome Stability Unit. “Polonium has a half-life of 138 days. This means that if that was the poison it will still be in the body and in the area – which makes it relatively easy to identify.”

As this story unfolds, it reads more and more like a hollywood blockbuster movie.

Download the current event article here.


Day 66: Radioactive Thallium Poisoning? November 21, 2006

Posted by Admin in Chemistry, Science in the News, Test.

After taking the second Chemistry test today (we’re all done with Chemistry!) we briefly discussed a fascinating news story about a former Russian spy who some believe may have been poisoned by radioactive thallium (Element #81: Tl). The article can be read online: Dissidents Say Poisoning of Russian Ex-Spy Linked to his Kremlin Critisism:

LONDON — A former Russian spy poisoned in Britain and now hospitalized under guard may have been targeted for his criticism of former colleagues and his investigation into the killing of a prominent anti-Kremlin journalist, friends and fellow dissidents said Sunday.

Since we’ve been discussing radioactivity a great deal lately, the symptoms the doctors have found should sound familiar:

A doctor treating Litvinenko told the British Broadcasting Corp. that tests showed he was the victim of poisoning by He’s got a prospect of recovering, he has a prospect of dying,” said Dr. John Henry, a clinical toxicologist who treated Ukrainian President Viktor Yushchenko in 2004 after he was poisoned during his presidential election campaign. Henry said thallium can cause damage to the nervous system and organ failure, and that just one gram can be lethal.

Radioactive thallium has a relatively short half-life, so doctors are not positive about the diagnosis. They say they won’t be able to detect any traces of Thallium in the victims bloodstream because it has already decayed.

Day 65: Test Prep November 20, 2006

Posted by Admin in Chemistry, Test.
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Today we took an egg quiz (ungraded – intended soley as a self-evaluation of understanding) as a way for students to see the fomat and content of test questions and assess how well they know the topics. The performance was mixed, but provided some good feedback on which areas students should focus their studying attention. The test is tomorrow and the study guide can be found in the post below (Day 64). The after-school study session today is when we will discuss the answers to all of the 15 short-answer questions on the back of the study guide. For students who could not attend the study session, they were invited to inquire about any questions they had either in class today or before school tomorrow.

When we return from Thanksgiving break we will begin our Astronomy unit!

Day 64: Test Prep November 17, 2006

Posted by Admin in Chemistry, Test.
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Today began with students completing the “Learned” column of the K-W-L activity that we began at the opening of the chemistry unit.  On this form, students documented what they learned during this lesson.  Following the completion of the KWL, students worked on organizing their science binders, weeding out old unnecessary papers and organizing the important information for the upcoming test.  They then began working on the Chemistry Test #2 Study Guide questions.

The after-school study session for this test will be held on Monday afternoon from 3:15-4:00 and the test is on Tuesday.

Day 63: Plasma November 16, 2006

Posted by Admin in Chemistry, Homework.
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After turning in the Fireworks article response questions, today we discussed plasma. We started by discussing its definition as the fourth state of matter. We then talked about several examples of plasma both here on Earth (flourescent lights, lightning, the Northern Lights, etc…) and in other parts of the universe (stars). The plasma worksheet (#2.7) is due at the start of class tomorrow. Remember the back side (2.4) is not due tomorrow, but we will do it at a later time, so don’t cross it off.

Also today, the Chemistry Test #2 Study Guide was made available to all students.  Tomororw we will begin preparing for the test and on Monday we will review all hour.  The after-school test study session is Monday afternoon from 3:15-4:00 during which time we will answer all of the short answer questions on the back of the study guide.

Day 62: Fireworks! November 15, 2006

Posted by Admin in Chemistry, Homework.
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By demonstrating the flame tests of five common elements (Calcium, sodium, barium, copper, and potassium) we were able to observe the color that is characteristic of each element (Red/orange, orange/yellow, yellow/green, green, and purple, respectively). It is different chemical compounds such as these that are used in fireworks to give them their color. We also talked about how and why different elements give different colors before observing the oxidation of Magnesium (bright!) in class.

The Radium Dials projects were due today and most students turned them in on time.

The Fireworks Reading and accompanying Fireworks Response Questions were assigned at the end of class. The response questions are due at the start of class tomorrow!

Day 61: Marie Curie and Radioactivity November 14, 2006

Posted by Admin in Chemistry.
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Today’s class started with the viewing and follow-up discussion about a short 3.5-minute video clip on the life of the famous French chemist Marie Curie. You can see the video yourself here at youtube or view it below. Why did she face such an uphill struggle with her work on radioactivity? Don’t forget that her accomplishments, discoveries, and inventions are all fair game for next week’s test.

After the video, the bulk of the class period was spent working on the Radium Dials projects that are due at the beginning of class tomorrow.

Day 60: Egg Quiz, Radium Dials November 13, 2006

Posted by Admin in Chemistry.
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After a challenging egg quiz over Radioactive Decay and balancing equations, students had some time to work on their Radium Dials projects.  We will have more time to work on these projects in class tomorrow and they are due at the start of class on Wednesday.  See previous posts for copies of all of the handouts that pertain to the radium dials projects.
The schedule for this week is as follows:

  • Monday (11/13):  Egg quiz, Project work time
  • Tuesday (11/14):  Marie Curie video clip, Project work time
  • Wednesday (11/15):  Fireworks!
  • Thursday (11/16):  Plasma
  • Friday (11/17):  Preparation for upcoming test

On Monday (11/20) we will spend more time reviewing for the test and there will be an after-school study session that day (3:15-4:00).  The test will be on Tuesday, the last day of class before Thanksgiving break.

Day 59: Radium Dials Project November 10, 2006

Posted by Admin in Chemistry, Homework, Links.
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Image showing a radium watch dial on the right and a second image on the left showing the areas of the watch that are the most radioactive (dark shading). Image source

Today we began the “Radium Dials” project. This project started with research from the Radium Dials Reading handout that focused on the Radium Girls of the early 20th century. This handout should be used to write at least one full page (double sided, or two single-sided pages) of notes on the topic. While you are working on the notes, keep in mind which type of project you’d like to do. You can read about the full details for each project type on the Radium Dials Projects List.

If there are other project types that you would like to complete instead of the five I have listed (such as a persuasive speech or a PowerPoint presentation), run the idea past me and I am likely to approve it. If you would like, I’d also like to set aside some class time for you to present the project to the class. Note you must get prior approval before straying from the 5 listed projects though.

Below are some links to some examples of each type of project.

More links to information about the Radium Girls:

Day 58: Radioactive Decay Post Lab November 9, 2006

Posted by Admin in Chemistry, Homework.
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Today started with a discussion about the exponential curve that defines the graphical representation of the half-life equation (as shown above).  Following this discussion, students worked on the Half-life Post-Lab with their partner.

Following completion of the post lab which is due tomorrow, everyone should staple all four pages of the lab (the pre-lab, the data, the data analysis, and the post lab) together along with a scoresheet on top to be turned in.  This completed lab is due in class tomorrow.  We will then begin working on the Radium Girls research project. Some students already began reading and taking notes on this project.  We will have more time to complete the notes and begin the project in class tomorrow.