I really love the periodic table. The table is so beautiful in that it explains so many properties of elements and can predict so many things. I love the periodic table so much that I have it on my shower curtain at home.
Unfortunately, many of my lovely adolescent students fail to see and appreciate the beauty of this amazing scientific structure. Also unfortunately, both my state and national standards mandate that, at some point in their education, students need to be able to use the Periodic Table in a meaningful way. The objective is in middle school in the Texas Standards:
8.5C interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements
And in high school for the Next Generation Science Standards:
HS PS1-1. Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms
One thing students usually are interested in and understand, though, is food. Specifically, snack food.
To introduce the idea of a specific arrangement of the periodic table in which the position of an element can be used to predict its properties I tell a little story about snack food and ask for my students’ assistance in solving a problem.
“My neighbors are blind,” I say (this is actually true, so my kids have heard stories about my blind neighbors before). “The other day my neighbors asked me to come over and help them get their pantry organized so they could more easily find their snacks. Sometimes they wanted salty snacks, sometimes sweet, sometimes spicy, and they could never tell which is which. They needed a way to have a system for knowing which snack was where.”
“Can you help them? They have three shelves in their pantry and lots of snacks. How would you organize all their snacks in a way that you could describe to them how to predict what went on which shelf?”
I then provide the students with cut out cards that have pictures of a wide variety of snack foods. The pictures are shown below and you can download a copy here.
The students then work in their table groups to organize all the snacks into three, and only three, piles.
When I tell the story using my blind neighbors, I’ve noticed students tend to organize by package shape, but I remind them that the shape doesn’t determine what is inside and what is inside is what counts! Students come up with a variety of groupings from Sweet, Salty, and Mixed, to color, to time of day (i.e. breakfast, afternoon, evening) and many many more. I do notice a tendency to classify as “healthy” and “not healthy,” which brings up a good discussion of what is “healthy” anyway and to promote an “all foods fit in moderation” philosophy
Depending on time, I either have the students elect a representative to stand up and explain their organization to the class or I ask all the students to do a gallery walk to see how different groups organized their snacks differently. We discuss how all the arrangements make sense in their own way, as long as you know the way things are organized. It is also fun to sometimes pick a random snack and ask students where it would go in their arrangement and see if they can pick out where that snack would go in ANOTHER group’s arrangement.
All this talk of snacks and organizing gets kids thinking and paves the way for reviewing that quintessential middle school science topic of the three types of elements on the periodic table: metals, nonmetals, and metalloids.
I explain how, just like we had three shelves in the pantry, scientists have three “shelves” that they use to classify elements. The elements on the “shelves” are mostly similar and you can predict the properties based on the arrangement if you know the pattern, just like you could predict the snacks on the shelves if you know the pattern. Most of my students learned metals, nonmetals, and metalloids before, so we just review the properties and introduce the essential vocabulary using this little tiny foldable
(print double sided, cut in half down the middle so one periodic table is on each half, fold the top over the bottom and cut on the dotted lines so each flap lifts to reveal the appropriate section of the periodic table).
In 6th grade in Texas the students learned the vocabulary:
TEKS 6.6A compare metals, nonmetals, and metalloids using physical properties such as luster, conductivity, or malleability
So once we finish the foldable reviewing the basic parts – metals, nonmetals, and metalloids – the next lesson is devoted to reviewing and applying those wonderfully big science words along with others like “brittleness,” “ductility,” and “translucency.”
Come back next time for that fabulous lesson…..