What are we learning and why are we learning this? Content, procedures, or skills.
Tier II: High frequency words used across content areas. Key to understanding directions & relationships, and for making inferences.
Tier III: Low frequency, domain specific terms.
Building on what we already know
Make connections to prior knowledge.
What is a “mole?”
It’s just a way of counting that makes it easier to solve practical chemistry problems.
We use moles to talk about extremely large numbers of very tiny objects (e.g. molecules, atoms or electrons.)
You already know that we use words to describe units, like
dozen = 12 of something
gross = 144 of something
ream = 500 sheets of paper
kilo = 1,000 of something
So moles are kind of the same thing – just larger, and with a number that, at first, seems odd:
mole = 602,200,000,000,000,000,000,000 of something
mole = 6.02 x 10 23
(Well, not exactly. It is really 602,214,179,300,000,000,000,000,
but we’ll round off.)
What does a mole of atoms look like? Here you can see a mole of aluminum atoms, copper atoms, and of carbon atoms.
Wow, even though there are billions of billions of billions of atoms, they still add up to small volumes. So each atom must be pretty small!
Ok, I get that we might need a big number.
But instead of 6.02 x 10 23 why not make it simple,
like 10.0 x 10 23 ?
So how did the concept of the mole develop? Why is it defined the way that it is?