One of the classes I was subbing last week is just starting its chemistry unit and learning the periodic table.
Moles? And … atomic peas?
Moles and atom size are abstract concepts, due to their extremes in quantity and size, that students have difficulty getting their heads around. A few years ago, I had created a page on my Teaching Resource site that helps with visualization of these concepts. My hope is that my page represents atoms and moles in friendlier terms — peas, a more concrete perspective students can sink their teeth into.
Yesterday I shared this page on Twitter, thinking that other teachers would also be studying the periodic table and molar chemistry.
And was I correct. It turns out yesterday, October 23, was Mole Day in North America.
Parco della Burcina di Biella – Barbagianni © 2011 Giovanni | more info(via: FlickrStorm)
I admit, I never heard of Mole Day before yesterday. Similar to Pi Day, March 14 (3/14) in North America or July 22 (22/7) in the rest of the world, Mole Day celebrates a milestone in human knowledge by matching that milestone to a calendar date (10/23). In this case, the celebration recognizes Avogadro’s Number, 6.02×10^23, the number of unit-entities (atoms or molecules) in a mole. There were even tweets yesterday that Mole Day should be celebrated from 6:02 am to 6:02 pm, only half a day, just like April Fools’ Day in many countries of the world. I like that.
Last year, I created a Notebook page with Web links to help my students understand the elements in the Periodic Table. It was a simple page; the links were the emphasis. It grabbed my students’ attentions and provided them with dynamic resources from outside of the classroom for either basic or enriched learning.
Update: I had many of the links below, and quite a few more, on the same pages as my Green Pea Analogy when I first published this post. However, I have since moved these periodic table links to their own page to give them the presence they deserve. Visit these pages to learn more about moles and the periodic table, and enjoy.
1. Periodic Table
In particular, the most useful site is Michael Dayah’s dynamic Ptable in which almost anything periodic and elemental can be learned. I can not recommend this site enough. Similar sites, with less information, are Chemicool’s and Spectrum’s periodic tables.
For further information on elements, a Periodic Table of Videos offers videos illustrating the elements and their behaviours through empirical experiments. And to show students that no this is not the only periodic table that ever existed, The Internet Database of Periodic Tables shows all the periodic tables ever made from Ancient times to today (literally).
2. Energy States and Orbitals
This really confuses students and it all has to do with our insistence on “orbitting” or “ringing” electrons around atom nuclei. I recommend four sites: Energy State and Atomic Orbitals, Schrödinger’s Atom, a Rotating Tetrahedron (to illustrate the Pauli Principle and Hund’s Rule) and What Atomic Orbitals Look Like.
3. Electron Filling and Configuration
Again, students have a hard time visualizing energy shells, sub-shells and electron configurations. Likely, this stems from the perpetual “orbitting electron” misconception. Several of the previous sites continue to explain these concepts. In addition, Electronic Configuration of Elements and How do I read an electron configuration table? offer more information. And finally, here is a table of electron configurations.
4. Periodic Table Puzzles
There are several sites and applications that offer puzzles and games to help students learn the periodic table. Three of these are: a periodic table puzzle and periodic table games here (free) and here (cost).
5. Music Videos
Atomic Structure and the Periodic Table offers an in-depth explanation of the elements and periodic table. Hydrogen Atom in Scale shows students just what an atom looks like to scale (lots of empty space). 3D models of molecules offers a selection of molecules made from the elements. Isotopes in the Solar System shows the newly discovered composition of isotopes in the Solar System, showing that yes atoms and isotopes are important in post-school careers and real life. Consider also the Earth’s aurora. The Solar System in Scale and The Scale of the Universe show the scale of the Universe in the other direction.
Update: Visit my Green Pea Analogy and Periodic Table pages to learn more about moles and the periodic table, and for more information and links on these concepts. I used to have these materials on the same page, but since separated and expanded them. Among other things, they now have student and teacher versions for ready classroom or home use. Enjoy.
This post was inspired by a small group activity I created for the class I was subbing last Friday. My students just did not understand how to balance ions when creating salts, so I abandoned the lesson I was asked to teach on Friday and created a salt creating exercise so I could help student groups as they worked on their puzzles (salt names). I found on Thursday that the one on one attention helped the kids, but there were too many of them to help individually for the time they needed. The students were unanimous in stating that the exercise was helpful. I am glad; I took a risk abandoning my assigned lesson in the slight hope that in the end my students would benefit more by doing this.Follow @stefras