Chemistry 11-18-21 Binary Molecular Formulas

CHEMISTRY: Do you feel like you have letter and numbers swimming in your eyes? This is one of those times that paying attention to details is super, super important! Here’s the lecture from Thursday on writing formulas and names for binary molecular compounds. Part of it’s really similar to what you learned to do for ionic compounds, but another part is totally different. Details!!

Make sure you keep everything straight. Do something that will organize all the information for you, so you won’t get confused. Also, don’t forget the lists you have to memorize – it’s getting larger and larger!! And practice, practice, practice!!!

Need extra practice? Help session??


flickr photo by Roger Smith

Physics 11-18-21 Work & Energy

PHYSICS: Funny thing about words, all this work you thought you’d been doing, was it work after all?

Great job today on making connections between work and energy! I think you’ll like using the work-energy theorem, it’ll save you some time and a couple of steps. Don’t forget about friction!

Physics 11-17-16 Work & Energy from Tammy Skinner on Vimeo.

flickr photo by *hb19

Hon Chemistry 11-16-21 Empirical & Molecular Formulas

HON CHEMISTRY: Now that you know how to write chemical formulas, you are going to be amazed at what you can do with them! I love the way you are able to think through what you know and what you need to find a solution. Today you are going to use that to find empirical formulas and molecular formulas all by yourself – well, almost by yourself. 🙂

Be sure and practice – if you don’t it’ll get all turned around and you’ll end up leaving off an important step. 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.

Are you starting to catch on to the steps? It will be good for you to memorize them, but would it not be just tons better to understand why you need each step – backwards and forwards, so then you wouldn’t need to memorize them at all!

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! 🙂


flickr photo by Darwin Bell

Hon Chemistry 11-15-21 Percent Composition

HON CHEMISTRY: Great job today! Way to apply chemistry to your everyday life!!

I think you’ll find that percent composition problems are super easy to catch on to. First, though, be sure you know which “type” of percent composition you’re trying to fine. Also make sure you can write chemical formulas (I won’t give them to you!) and that you’ve memorized the formulas for acids and those chemical names and formulas for common substances. It’s just plug and play from there! 🙂


flickr photo by Τϊζζ¥

Chemistry 11-15-21 Chemical Formulas with Polyatomic Ions

CHEMISTRY: How about cranking it up a notch?! First we did binary ionic compounds, and now, let’s tackle formulas with polyatomic ions. Something absolutely necessary – you have got to memorize polyatomic ions – or better yet, learn them! And practice, practice, practice!!

Another great idea, click here for a copy of the Hints for Naming Chemical Formulas Flow Chart, or find it under the Worksheet/Handouts Tab. Follow it every time you name chemical formulas!!


flickr photo by skycaptaintwo

Chemistry 11-10-21 Chemical Names & Formulas

CHEMISTRY: Great job learning to name binary ionic compounds – and even beginning to write formulas!

Speaking of formulas, what is your plan for all the memorization in this chapter? Word of warning – don’t wait to the last minute!!

Super important – the secret for the next few days and this entire chapter is DON’T GET BEHIND! Keep up with me and practice, practice, practice!

Hon Chemistry 11-10-21 Using Chemical Formulas

HON CHEMISTRY: So the little mole turns out to be a pretty big deal – and a very handy tool!!

Great job today! Here’s discussion on formula mass and molar mass, and then using molar mass and Avogadro’s number as a conversion factor. You’ve got a couple of great tools – so now think through the problems and go forth and conquer!! Be sure and practice them so you don’t forget!


Photo by ahmad kanbar on Unsplash

PHYSICS 11-9-21 Vertical Fish Forces & Forces with Pulleys and Friction

PHYSICS: Not sure if you’d ever find a fish on an elevator, but you sure could treat the problem like it was! Here a look at the fish on a line problem, and then, a different take on forces – an application of horizontal forces, vertical forces, friction, all at once!

Wow! Amazing job solving these problems – can you now go see if you can solve them by yourself?


flickr photo by Elisa Dudnikova

Hon Chemistry 11-9-21 Moles, Molar Mass & Avogadro’s Number

HON CHEMISTRY: So….you think if his work helped us understand something as significant as the number of something in a mole they might name something after him? They did! Go figure! Another name for the number of anything in a mole is Avogadro’s Number. That would be how many?

You caught on super fast today! Remember, it’s all in terms of one mole. The mass of one mole, the molar mass, is the average atomic mass of the element in grams (periodic table). And the number of atoms in one mole is …. well you know that. Speaking of moles, isn’t he cute? Well, beauty being in the eye of the beholder and all. Hmmmm………


Image source blog.ibts.eu/wp-content/uploads/2009/02/mole2.jpg