I love this time of year; the start of stoichiometry. It feels like I'm at the cusp of teaching them "real chemistry." But it can also feel intimidating. So I tried something new. I taught them the concept of the mole without having them take a single note. By the end of one period, they were converting among moles, atoms, and grams. In their head. Oh, and they had fun doing it.
I started by asking them two silly questions:
Which has more things, a dozen cotton balls or a dozen bricks?
Which weighs more, a dozen cotton balls or a dozen bricks?
They sound like some of those questions we would bring home in third grade trying to trick our parents. They aren't a trick. They are easy.
I had a graduated cylinder with 18 mL of water in it. We played a guessing game. They had to bet the person next to them how many molecules were in the cylinder. Closest without going over. Then we wrote some of their guesses on the board. I'm not joking when I say the guesses ranged from 200 (don't ask me) up to 7 trillion.
Then I wrote the real answer on the board just slow enough to be uber dramatic.
60220000000000000000000
What a number! Even the 7 trillion guess (which was placed by the funny girl trying to be silly by guessing so high) is painfully small. So I introduced the mole.
Atoms are really freaking small. So there are a whole lot of them in anything we can see. So when we count atoms, it better not be by the dozen. It's by the mole. Which is this number of things.
I'm going to show you how I used Up & Atom to connect these ideas in their heads. You are more than welcome to make your own cards on scraps of paper. I did that for years with success. The idea is that you are allowing their minds to wrestle with content in a new way.
Then I handed out decks of Up & Atom. I told them to pull out six yellow cards (which show the number of atoms). They had to sort their cards from the fewest atoms to the most. It's pretty easy, just look at the numbers. Their cards looked like this.
Then they had to figure out how many moles each card represented. Knowing the value of one mole, they pretty quickly calculated that there were cards of one, two, three, and four moles.
Then they took out six red cards, which have grams on them. They were told to put them in order from the fewest atoms to the most. They looked at each other, talked a little, and slowly just put them in order of mass.
Now you and I look at this list, and know instantly that it isn't right. So I get to ask an important question. Which weighs more, a dozen cotton balls or a dozen bricks? And now I can connect in their minds that not all atoms weight the same. We have already learned at an atomic level what average atomic mass is. So I get to briefly teach them the connection between the submicroscopic world of atomic mass units and the real world of molar mass. Yes, one atom of hydrogen has an average mass of 1.01 amu. But if you have a mole, it has a mass of 1.01 grams. And you can see a gram! So they look at their first card and realize that 3.03 g is more moles than just one. It's three!
And instantly they are scouring their periodic tables, and rearranging the cards. I could hear them saying things like, "This is two moles, it belongs above that card..." 15 minutes ago, they didn't know what a mole was and now they are using the language of a chemist.
Finally I have them pull out the blue cards. These are labelled in moles. Put these in order from fewest to most atoms. Ha! They are done in two seconds. This is too easy. Everything is easier if you just convert it to moles. And instantly, I have them. They count by the mole.
And now it's time to gamify their experience. I had the kids shuffle the cards and deal them all out to the five or six kids around the table. Play war! The card with the highest number of atoms wins. If there is a tie, the card with the most mass wins. They all know how to play war. They get competitive and want to win. And I don't have to teach any more that period. The kids do it. I sat back and listened to conversations about moles and grams and atoms and how to convert to moles. The kids who were slow got pulled along by the fast kids who want the game to go more quickly. Everyone was engaged.
And my dirty little secret was alive and well. I was teaching them stoichiometry and they didn't even know it.
Teaching it this way made the process faster, more engaging, and much more fun for the kids. And we weren't even playing Up & Atom by "the rules" yet. That would come a couple days later. You will be amazed at the speed with which kids can pick up this somewhat nebulous concept when gamified.
If you are interested in getting a class set of Up & Atom, you can order right here. I am so happy to see more teachers engaging their students with games that are competitive and tie directly to the curriculum. You will love it.
Here is a short video outlining this very concept!
