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Lake Ontario over 80% frozen

2/25/2015

Wow, February is almost over! I hope your classes have gone well and the weather has been cooperating with you.

There isn't much money left in most 2014-2015 science department budgets. For inexpensive chemistry lab ideas, buy my lab book "Chemistry on a Budget" for $20.56 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one double-sided handout.

The past two blog entries, 02/11/2015 and 02/18/2015, were about Nuclear Chemistry. With the current cold weather, an interesting phenomenon has occurred with the Great Lakes freezing over.

Here is a recent television news article:
http://www.cnn.com/videos/weather/2015/02/24/lklv-weather-extreme-cold-in-us.cnn

Lake Ontario, the largest of the Great Lakes, is over 80% frozen – this situation can lead to discussion of the special properties of water.

I have written two past blog posts -- one about Heat & Energy (on 03/05/2014) which discusses the measurement of heat energy transfer and shows a lab regarding Specific Heat; and, the other titled Dipole-Dipole Forces, etc. (on 03/16/2014) which includes a detailed discussion of Hydrogen Bonding.

Here is one newspaper article about this phenomenon:
http://thevane.gawker.com/why-wont-lake-ontario-freeze-over-1536706402

From this article:
A reporter for the Toronto Star asked a climatologist with Environment Canada (Canada's version of the National Weather Service) why Lake Ontario has so little ice during even the harshest of winters. The expert listed three reasons as to why the lake sees less freezing than its four counterparts:

- Lake Ontario is deep, so it retains more heat than the other four lakes.

- The Niagara River feeds water into Lake Ontario from Lake Erie, providing agitation which keeps the water's surface from freezing.

- Its geographic location protects it from the brutal temperatures that Lake Superior and northern Lake Michigan experience most of the winter.

Here is a Syracuse, NY newspaper article briefly discussing the phenomenon:
http://www.syracuse.com/weather/index.ssf/2015/02/lake_ontario_ice_lake_effect_snow_watertown_cold_february.html

Students could be required to research this phenomenon either as a Class Assignment or for Extra Credit. I’d love to hear about your results of this research.

Check out the Topic List to help you to find past Blog entries.

Have a good weekend!

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nuclear chemistry -- part II

2/18/2015

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Happy Wednesday! I hope you’re enjoying your days off and are keeping warm!

There isn't much money left in most 2014-2015 science department budgets. For inexpensive chemistry lab ideas, buy my lab book "Chemistry on a Budget" for $20.56 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

My last blog post was an Introduction to the language of Nuclear Chemistry.  I've gotten away from listing Objectives, so for this blog post:

Objectives
1.  Explain the process of Nuclear Fission and Nuclear Fusion.
2. Recognize and balance Nuclear Reactions involving Fission and Fusion.
3. Define the Half-Life for a substance and read various reference tables to determine the duration of the half-life.
4. Calculate the half-life of substance, how many half-lives will occur given a certain period of time, and the amount of the original radioactive substance that remains (grams, fraction or percent) given a period of time

Here is an 11-minute video presentation about Nuclear Fission, Fusion and Nuclear (fission) Reactors:

Atoms with unstable nuclei (either naturally or artificially through bombardment with subatomic particles) will release mass and energy until they are stable.

Half-life is the amount of time it takes for one-half of a sample to undergo nuclear decay. Sometimes half-lives are very short and study of these substances is difficult; some half-lives are brief but persist enough to allow for use as nuclear tracers (a medical application); and, some half-lives are very long (thousands of years) which is the concern about the waste from nuclear power plants.

There is nothing that can be done to speed up or slow down the time it takes for a nucleus to undergo decay.

A useful table of isotopes, the nuclear particles they emit and their half-lives is on Page 6 in Table N of the NYS Chemistry Regents Examination Reference Table. http://www.kentchemistry.com/newRT.pdf

Here is presentation solving half-life problems:

In the 1st problem, he determines the number of half-lives that have passed by dividing the total time by the time per half-life:

44 days = 4 half-lives

11 days/half-life

Also, I put numbers by the brackets to label how many half-lives have been calculated. Eventually students will feel comfortable not labeling, but they’ll appreciate it while learning the skill.

In the 3rd problem, he omits the units when solving for half-life – putting the units in is a healthy habit and should be required!

At an introductory level, the Chemistry involved is pretty much as simple as this, so I won’t be discussing the math he talks about at the end of the video.

Here is a link to a page with several worksheets about Nuclear Half-Life:

http://mrsmastin.weebly.com/uploads/2/0/7/3/20730250/half_life_practice.pdf

Here are several questions from the NYS Regents Examination, both multiple choice and short answer, for your reference/use:

http://www.mrbeauchamp.com/NuclearRegentsReview.pdf

The Uranium Disintegration Series table on Page 3 (above Questions 32 and 33) could be assigned where the student writes out all of the nuclear reactions in the series, perhaps as an Extra Credit opportunity.

There aren’t many labs that can be completed for this topic, but there is one lab in my book, Chemistry on a Budget, about Half-Life, as well as ideas for articles for use with your class. Links for purchasing the book are at the beginning of this blog entry.

This is an interesting topic for students to research, as a class assignment or an extra-credit opportunity. The accidents at nuclear power plants (Three-Mile Island, Chernobyl, and most recently Fukushima) and the original atomic bombs in World War II, as well as the debate about the use of nuclear fission as an energy source provide many topics to research.

As an extra, here is an interesting video about a 14 year old who built his own fusion reactor:

Check out the Topic List to help you to find past Blog entries. I hope it helps!

Have a good vacation!

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introduction to Nuclear chemistry

2/11/2015

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Happy Wednesday! Wow, it’s almost Presidents’ Day, and maybe Winter Break, too! Snow may have been affecting your part of the country, but it won’t be winter forever!

There isn't much money left in most 2014-2015 science department budgets. For inexpensive chemistry lab ideas, buy my lab book "Chemistry on a Budget" for $20.56 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

I revisited Atomic Structure last week, and I’ve just realized that I haven't written anything about Nuclear Chemistry! Oops… I did talk about atomic symbol notation briefly on 02/26/2014, but it was just a reference.

Some teachers cover Nuclear Chemistry at the end of the school year -- it can be useful to review Atomic Structure while covering this topic, which prepares a little for final examinations. In my later teaching years, I would cover Nuclear Chemistry while I was teaching Atomic Structure to save time during the school year. Either approach is a valid choice.

Atomic structure at an introductory level is typically protons, neutrons and electrons. I posted previously about this on 02/16/2014 and 02/04/2015. Symbol notation is a typical method to show a lot of information quickly and the student is expected to be able to interpret it.

Here’s one example:
http://intranet.micds.org/upper/science/text/Chemistry_Textbook/Ch02/Section_0202.html

Student knowledge of Symbol Notation is necessary because it is used to represent subatomic particles, especially in Nuclear Reactions.

A useful table of subatomic particles is on Page 7 in Table O of the NYS Chemistry Regents Examination Reference Table. http://www.kentchemistry.com/newRT.pdf

Isotopes of elements are also named using the name of the element, then a dash, then the mass number. For example, the symbol above would also be known as Helium-4 . A typical example would be hydrogen, which is Hydrogen-1, Hydrogen-2 (aka deuterium) and Hydrogen-3 (tritium). The atomic number (proton #) does not change with the element, but the neutron number can change, providing various mass numbers or isotopes of the element.

A typical skill for this unit is that of balancing nuclear equations. It’s a pretty reasonable skill, the student makes sure that the total of the mass numbers and atomic numbers on the left side of the equation equal the total of the mass numbers and atomic numbers on the right.

Point out to students that if they are given the atomic symbol, they can determine the atomic number (# protons) using The Periodic Table.

Here is one link with several Nuclear Equation worksheets:

http://www.mr-gracias.com/chemistry/chapters/ch%204%20Atomic%20Theory/TypesOfRadiation-Student.pdf

Here is a 10-minute video with an introduction to Nuclear Chemistry:

It does start talking about Half-Life – I will focus on that topic in next week’s post.

Check out the Topic List to help you to find past Blog entries. I hope it helps!

Have a good vacation!

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atomic structure revisited

2/4/2015

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Happy Wednesday! Just a little more time before many of you have a Winter Break, so it’s a rush to get teaching units finished by February 13th.

If you’re a new teacher, try to give any quizzes or tests before the last day of school because some students may leave early for vacation with their families – you may have experienced this at the end of December.

There isn't much money left in most 2014-2015 science department budgets. For inexpensive chemistry lab ideas, buy my lab book "Chemistry on a Budget" for $20.56 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

I was talking about Gases for the past few weeks, but now I am revisiting Atomic Structure. I posted about Atomic Structure on 02/16/2014 – check it out!

Atomic Structure and the challenges of investigating it are easy to explore with “Mystery Boxes” (also known as “Black Boxes”). Students may have encountered this lab in younger years, but it still is useful to show the challenges of determining how the atom is built.

I made my own mystery boxes, wrapped them in brown paper, labelled each and had a KEY so I knew what was in them. They ranged from a single object to a barrier for the object to work around.

One year, I had my students perform the lab and then had them create their own “mystery boxes” or donate empty shoe boxes or leftover items from home. I did warn them not to take a shoebox and just dump out the shoes or to take objects that their household was still using.

Here is a very simple Mystery Box Lab (3 pages) where students research the history of research about Atomic Structure including Rutherford’s experiment:

http://www.lmtsd.org/cms/lib/PA01000427/Centricity/Domain/219/mystery%20box.pdf

This lab could also be completed with a blank sheet of note paper with the directions of what should be recorded on the board.

After the Mystery Boxes lab, the history of the development of science's picture of the atom could be discussed.

Here is a video (10 minutes) to provide an overview of the History of Atomic Structure:

It’s a lot of information, and the narration can be very fast. (sorry about the subtitles -- see if you notice the “Breaking Bad” reference)

Here is another 11 minute video that provides an overview of the History of Atomic Structure starting with Dalton:

It discusses the experiment leading to the discovery of the neutron (starting at 7:37 minutes), which is not typically discussed very much.

Here is a crossword puzzle to provide an overview of the History of the Atom:

Check out the Topic List to help you to find past Blog entries. I hope it helps!

Have a good weekend!

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Lake Ontario over 80% frozen

nuclear chemistry -- part II

introduction to Nuclear chemistry

atomic structure revisited

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