double displacement reactions

trying something new….trying to build a particle model to describe precipitation reactions.  So far, students are  saying that drawing out the ions are helping them understand dissolving, combining reactants and possibilities for recombined products.

The use the solubility rules to determine which is insoluble.

Revisiting something old.  making them write down the rule that proves new molecule is insoluble.

Next up:  molecular; complete ionic and net ionic reactions.

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Modeling chemical Reactions

The new trend in chemistry (which I agree with) is to have the students draw chemical reactions pictorially (models). I have been trying to incorporate this idea this year in chemistry, but I have this nagging “bug” in the back of my mind. “do the students need to know how to draw Lewis Structures before we have them representing molecules?

I remember the “Whole Language” idea that invaded the English classroom a few years ago which allowed students to ignore correct spelling of words, so they wouldn’t be throttling the flow of ideas onto a paper.

I feel that, without Lewis Structures, we will be doomed to repeat what history as deemed a bad idea.

I used to do an atoms-first approach to chemistry. Looks like I will be going back to this which can allow for Lewis structures before reactions.

Kahn Academy?

Interesting video about “watching” lectures.  http://fnoschese.wordpress.com/2011/03/17/khan-academy-and-the-effectiveness-of-science-videos/

Are students really learning or only hearing what they want to hear to justify what they already “know”.  I have the same problem with gravity that the video used as an example.

It is important that teachers in lower grade levels get the concepts right.  Students are much more receptive at the younger ages.  So, when we get them in high school, once they hear a topic they already know, they had better know it correctly, or they will more than likely not be corrected.

I like that the term “confused” was used as a sign of corrected misconceptions.