Chemistry 10-23-12 Chemical Formula Practice & Worksheet

CHEMISTRY – Yeah, don’t you wish it was as easy as this? The rules for writing chemical formulas, I mean. But no, there are about 50 million, and you have to keep them all straight! Do you need some extra help? Help session Friday morning, 7:15ish A.M.

Click here for the Chemical Formulas Worksheet.

First step – memorize what you are supposed to memorize – polyatomic ions, rules, etc. Next, organize your notes into what you do for ionic compounds, those with metals and polyatomic ions, and what you do for molecules, those with only nonmetals and metalloids. Then analyze every single compound you have to name or write a formula for – is it ionic? then you only use the Stock system. Is it a molecule – then you can use the Stock system or prefixes. Do you see what I mean?

flickr photo by Gord McKenna


Hon Chemistry 3-23-12 Molecular Formulas

HON CHEMISTRY: Happy Mole Day!!

Great job with empirical and molecular formulas today! The hardest part is that it’s not a set formula for you to plug and play, but if you’ll keep in mind that you’re really just looking for subscripts which are just moles, you’ll be able to think it through. Percent to mass, mass to moles, moles to smallest whole number ratio.

And then also remember what molecular formulas are – just a multiple of the empirical formula. Keep that concept in mind, and you’ll have no problem remembering to divide the molecular formula mass by the empirical formula mass to find X! Easy peasy! Help session?

flickr photo by Elizabeth The Queen Of All Things


Physics 10-23-12 Equilibrium

PHYSICS: So, how is the balance in your life? Here’s the lecture from Thursday on net force, equilibrium, and equilibrants. Were you experiencing a little déjà vu? Tonight’s homework is Pg. 143 – 146: 7 – 12; tomorrow night it’s the Equilibrium Forces Worksheet. Good job today!

Thank you, Ben and Darby, for being such good sports!!

Image source…/2009/08/tug-o-war1.jpg