Monday, November 1, 2010

Ionic Bonding

We started class by collecting some worksheets at the front table. The worksheets were pages 9, 10, and 11. Mrs. Mandarino also gave us new Periodic Tables that have new information on them that should be helpful to us. REMINDER. SCRIBE POST ARE GRADED, SO IF THEY ARE ASSIGNED, PLEASE DO THEM. After that, we went over Thursday's homework (worksheet pages 4 and 5). Not many people did the homework though, so Mrs. Mandarino stamped it for extra credit. Pages 4 and 5 were about Ionic Formulas and Forming Ionic Compounds.
Ionic Formulas:
We went over how to make a formula based from a pair of Ions.
Ex. K+ and O2-
There are three ways to do this, Common Sense, Common Denominator and Criss-Cross.
Essentially, K+ and O2- will become K2O


We are always trying to pair up the ions so that they will be neutral.
If there are a group of ions and you need to choose which should go together, choose the two that will have opposite charges and will "cancel" each other out.
Ex. Na+ S2-, I-, Zn2+
Na+ and I- should go together because one ion has a +1 charge while the other has -1 charge. Their opposite charges will cancel each other out (which is our goal).

After we went over the homework/extra credit, we (as a class) did pages 6 and 7 together.
6 was also about forming ionic compounds, but 7 was about Polyatomic Ions.

Polyatomic Ions
  • Poly=Many
  • Atomic=Atom
  • Ions made up of many atoms
  • ex: NO3 -1
  • There are many negative Polyatomic Ions bu only one positive Polyatomic Ion.
  • NH4 +1

Polyatomic Ions are always written in a specific order. The positive part is written first and then the negative part is after.

Cation: Positive Ion. You can remember this by the t in cation. The t looks like a + for positive.

Anion: Negative Ion. You can remember this by the n in anion. N stands for negative.

Also, the new periodic tables that we metioned before have names of some polyatomic ions which is the updated part.

The homework was the rest of page 7 and page 8. For the homework, we haven't learned the names part yet, so that part doesn't need to be done. As always webassign is homework.

Have a good weekend and Happy Halloween!!

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