Periodic Table Web Analysis



Periodic Table Web Analysis

Scott Seiple

University of Pennsylvania

Chemistry 501

Summer 2005

The periodic table contains a wealth of information organized in a way that allows chemists to quickly gain an understanding of how atoms of elements are constructed and how they will behave in their environment. To beginning chemistry students, the periodic table often appears to be a somewhat random smattering of elements. Its shape and organization are especially mysterious to most students. There are a number of websites on the periodic table that help to explain trends that exist in the table. Some websites are truly exceptional at doing this while others are not as good. The goal of this analysis is to find websites that can effectively used by teachers in the classroom and by students for out-of-class assignments.

The organization of the periodic table is one of the most important concepts taught in chemistry. By finding an element’s location on the periodic table, one can get a good idea of that element’s structure and behavior. For high school chemistry students, some of the most important concepts that can be determined by looking at the periodic table are electron configuration, electronegativity, ionization energy, atomic radius, and ionic radius. While a number of websites do a fair job with some of these concepts only a few found do an exceptional job with all of these concepts.

Far and away the best website for seeing periodic trends was developed by the Amercian Chemical Society (ACS). This website can be found at . The website does require the plugin Shockwave which may need to be installed on school computers by an IT technician. Once accessed though, it does a wonderful job of displaying all of the previously mentioned characteristics in both graphic and tabular notation. Students and teachers can click on an interactive periodic table which will display element information. Graphics are large enough so that they can be easily seen when projected using a digital projector. It is very nice for classroom use because it demonstrates information clearly and simply. The interactive nature of the program also makes it attractive for students to use outside of the classroom. An example of a data window and a graphical window can be seen below.

There are few weaknesses to the ACS web site. Its primary weakness is its popularity. When preparing this review of the paper, the site was once not accessible in eight attempts to view the page due to high traffic. The need for the Shockwave plugin to view this page makes preinstallation of Shockwave necessary on any computer that will be used to view the site.

Another very good site with a large amount element information that will help students understand periodic trends was developed at MIT. It can be found at . From the main page there are links to pages that show a number of periodic trends. The window below shows the window appearing when the ionization energy link is followed. Actual values for each element are displayed in each periodic table cell.

Further down the page is a graph that shows the same information graphically. Unfortunately the graphs are fairly difficult to interpret. Students will most likely find the graphs difficult to interpret. One very nice feature of this site is that it presents the actual values for electronegativity, ionic, and molecular size in a way that is very easy for students to see in once glance. This would be a very nice site to send students to so that they can obtain data to construct their own graphs using Excel or other graphical analysis programs.

While this webpage is not as interactive as the ACS webpage, it does not require any plugins. This is an enormous advantage if Shockwave is not available. The page also loads very quickly in comparison to the ACS website and there were no issues with reliablilty when the page was tested. If the ACS webpage is not available this webpage has much of the same information. However there are also some features on the ACS site that are not available on the MIT website, most notably electron configurations and orbital filling diagrams.

After learning about periodic trends in class, a typical progression is to move to an investigation of how the properties of an element relate to its uses in society. Again, there are a number of sites that cover this material, but only a few of them are excellent. One of the better websites found is . It has a large amount of information about each element and is clearly laid out. Pages load relatively quickly. The site does not for all elements relate how the atomic structure of the element influences it properties and uses. It does a great job of presenting a large amount of element information. One disadvatage of this site is that pages on the site are rather graphics intensive. This slows loading time for the pages. If fast transitions are a must, this site is not suitable. It is the best resource found for student internet research about uses for a particular element.

Another nice site for human uses of elements is published by Chemical and Engineering News at . This site has some very good information about each element. It does a better job than at relating use to structure for most elements. The descriptions for some elements are fairly dense reading for most high school students. The page does load quickly and requires no plugins.

There are also a number of specialty sites. I teach environmental science and the site will be very helpful when integrating chemical concepts into the course. It shows the importance of a number of elements in ecosystems and includes quite a bit of physical data about each element. Another helpful site for environmental/earth science classes is . This site has a good deal of information about the source ores for elements and their biological impotance. A well-known and excellent site from Great Britain can be found at . This site has a large amount of information on uses of elements. It also does a nice job at discussing periodic trends.

Another aspect of learning about the periodic table is uncovering the history of the development of the modern periodic table and alternative periodic tables. There are a number of sites about Mendeleev and many are very good. Some of Medeleev’s orginal writing can be found at and . Both sites are nice as primary resources but they are not written a style that most students are accustomed to. Mendeleev’s original data is laid out on . This might be useful in having students construct their own periodic table and make predictions as Mendeleev did. One of the only quality sites to discuss the delopment of the periodic table after Mendeleev can be found at . This site has some very good information. It is clearly written and would make a good resource for a research project for students. In fact there are no periodic history websites that I would consider suitable for showing to a whole class. Images from some of the websites would be very helpful for PowerPoint and notes from Mendeleev’s orginal periodic table helpful for small group work, but none found are sutiable for use as a tool in direct instruction.

Finding good websites on alternative forms of the periodic table proved to be somewhat of a stuggle. One site that shows alternative periodic tables, but gives very little explanation is found at . A nice copy of the expanded periodic table can be seen at . No pages found gave satisfactory explanations for why althernative forms of the periodic tables were developed and for certain uses are presumably better than the standard periodic table.

Of the website found, on a few would be helpful for use in direct instruction. The two best that were found for direct instruction both dealt almost exclusively with periodic trends. The other sites were better suited to research projects completed by individual students. Though there is a large amount of information available on the web about the periodic table and period trends only a few manage to show that information in a clear or concise manner that is appropriate for high school students. The website mentioned here are the best found.

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