na + cl - na + cl - na + cl - na + cl - na + cl - na + cl - na + cl - na + cl - na + cl - na + cl -...
TRANSCRIPT
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Init 10/20/2010 by Daniel R. Barnes
WARNING: This presentation may contain visual images and other content that have been stolen from the world wide web without the permission of their owners. It is intended for use only by Mr. Barnes and his students. Please do not copy or distribute this presentation. Its very existence may be illegal.
Init 10/20/2010 by Daniel R. Barnes
WARNING: This presentation may contain visual images and other content that have been stolen from the world wide web without the permission of their owners. It is intended for use only by Mr. Barnes and his students. Please do not copy or distribute this presentation. Its very existence may be illegal.
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Na+
Cl-
Na+Cl-
Na+
Cl- Na+
Cl-
Na+Cl-
Na+
Cl-
Na+Cl- Na+Cl-
Na+Cl- Na+Cl- Na+Cl- Na+Cl- Na+Cl- Na+Cl-
Group leaders, come get one blue ball and one white ball for every person in your group.
Also get a bunch of toothpicks. You’ll need about four per person or so.
Put all the balls and toothpicks in your box and bring them back to your seat, but do not distribute them to anyone yet.
Group leaders, please, now, give one blue ball, one white ball, and four toothpicks to each person in your group.
What do think each white ball represents? Why?
What do think each blue ball represents? Why?
= ?
= ?
Everybody, connect your blue ball to your white ball with a toothpick.
How do these two ions feel about each other? Why?
What will be representing an ionic bond in this model?
What would you call a single sodium ion connected to a single chloride ion?
Why would it be wrong to call it a “salt molecule”?
+
In a compound like salt, what is the name for this attraction?
Now that you have a formula unit of sodium chloride bonded together, please find a partner. Bond your formula unit to your partner’s formula unit using two toothpicks.
Why would this be wrong?
This is much better.
Blue hates blue and white hates white but white and blue love each other.
Everyone who has a square of four ions, please find someone else who does and bond your square to their square using four more toothpicks. The result should look like a little cube. Try to make it as perfectly cubic as possible. This is going to be a crystal, not a wad of chewing gum.
≈
Everyone who has a square of four ions, please find someone else who does and bond your square to their square using four more toothpicks. The result should look like a little cube. Try to make it as perfectly cubic as possible. This is going to be a crystal, not a wad of chewing gum.
≈
Everyone who has a cube, find someone else who does and bond your cube to their cube so that you have a “brick” made of sixteen balls.
Anyone who has a brick, please find someone else with a brick, and join your bricks together to make a 4 x 4 x 2 “brownie”.
Now, whoever has the brownies, please bond them together to make the final cubic crystal. Ta-da.
Does it look something like this? Yay!
Xz+ Yn- Xz+ Yn-
Xz+Yn- Xz+Yn-
Xz+ Yn- Xz+ Yn-
Xz+Yn- Xz+Yn-
Please comment on this drawing.
Not all crystals are cubic!
“Tetrahedral”(four-sided pyramids)
“Octahedral”(eight-sided opposing pyramids)
[NOTE: not all crystals are water-soluble salts, either.]
Not all crystals are cubic!
“Hexagonal”(six-sided prism, shaped like a pencil)
Not all crystals are cubic!
“Foliated”(splits into sheets,
like pages in a book)
Na+ Cl- Na+ Cl-
Na+Cl- Na+Cl-
Na+ Cl- Na+ Cl-
Na+Cl- Na+Cl-