Teach the mole in minutes with this simple activity
I’m amazed at how much time I used to waste teaching the mole. Not any more.
Don’t get me wrong, I still teach the mole, I just waste less time!
By using this simple introductory sorting activity, kids have the light turn on really quickly and then start helping each other. Getting groundwork laid for the mole helps me make deeper connections later in the unit. Here’s how I do it.
Sort by the number of atoms.
I give each group of 4-6 students a deck of Up & Atom (though you could do it with your own cards too). Their first instruction is to take out four yellow cards, each with a different number on them. Then they have to sort them from left to right from fewest atoms to most. It sometimes takes a minute to get them to look at the exponents, but after that, it is easy to put them in order. 6.02 x 1023. 1.20x1024. 1.81x1024. And 2.41x1024.
It is so easy to sort them by the number of atoms, why don’t we just count by the atom in the lab? They easily answer because of the infinitesimal size of atoms. That is a good first connection.
Sort by the number of atoms by mass.
Next they pull out 4 different red cards which are grams. Now they sort them above the yellow cards from fewest atoms to most atoms. Of course, since this is the first day of the unit, the students have no idea how to do this. They stare at each other for a minute and then put them in order from lowest mass to highest. I let them make this error.
Every group will do this and I let them get settled on it. And then I tell them they are wrong! Their knee jerk reaction to fix it is to just reverse the cards from highest to lowest mass. They are still wrong!
This is the first time I write something down in the lesson. I write this phrase on the board.
1 mole = 6.022x1023 atoms = mass on the periodic table
With a couple of simple guiding questions, they begin to figure it out. “If I had 6.02x1023 atoms of nitrogen, how much would it weigh?” They figure it out to be 14 g. What if I had 6.02x1023 atoms of neon, would it weigh the same? Nope. It would weigh 20 g. Then I have them look through their cards and find a card that has one mole of atoms on it based on the mass.
Once they find that, usually a kid in the group will realize the method for converting to moles. Take the mass on the card and divide by the mass on the table to determine the number of moles. In a few seconds, that kid has it worked out for the group.
Pro Tip: If one kid is quarterbacking the whole process, give them four more cards and have them put in order, this time the quarterback can’t help.
On a second sort, the rest of the group starts to have the lightbulb turn on. It is a really cool experience to watch around the room!
Sort atoms by the mole.
The last cards I have them sort are the blue cards which are the moles. It takes them about 0.5 seconds to sort them. 1mole. 2 mole. 3 mole. 4 mole. Bam. Done.
I will ask them which metric is the easiest to sort. Obviously, it is the mole. Which metric is the easiest to use in the lab. This time it is grams. Which metric is most accurate for how reactions occur? Atoms. So, all of the metrics have purpose in different scenarios.
Play War.
After the majority of lightbulbs go on, I have the kids shuffle up and deal out the cards to play War. Each kid takes their stack of cards face down and flips over the top card at the same time. The winner is the player who played the most atoms. They will have to do some converting. The winner takes all the played cards and adds them to the bottom of their deck.
As the students are playing, you can move around the room and watch for kids who are lost. Sitting next to them as they play a game is less intimidating than failing a quiz. After a few rounds, I do an in-game quiz. Make one kid be the one to determine the winner while the others don’t help. Then each successive hand the next kid has to determine the winner.
I know that this process could seem too simple or elementary. Trust me, it’s not. You will watch kids make mental connections between atoms, mass, and moles in a matter of 15 minutes. Then as you expand into dimensional analysis, the conversions have some logic to them.
Do yourself a favor and teach the mole in 15 minutes without “teaching” the mole. It will be the best 15 minutes of chemistry time you can spend.
Don’t want to spend time to make your own cards? Try Up & Atom. Once they have done the sorting game, you can play by the real rules which is a trick taking game. The students bid on how many rounds they will win by having the most atoms on their card. It becomes strategic and engaging as each student is doing mental math in moles over and over. And playing a game is way better than another worksheet!
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