Chemistry 12-3-12 Isotopes & Average Atomic Mass

CHEMISTRY: Can you believe atoms are that small – and the nucleus even waaaaaay smaller! Here’s another picture of atoms from the IBM Almaden Research Center. These are iron atoms on top of copper. Being able to move atoms around like this was a giant leap in the field of nanotechnology! (Sorry about that, bad pun! 🙂 )

Here’s the lecture from Monday on atomic number and isotopes. It’s the last lecture for this chapter – and for this year!!

What did you think about Lise Meitner’s story? Amazing, huh? How are you doing on writing nuclear symbols? Also make sure you can use them to determine the number of protons, neutrons, electrons, etc. Did we get to the formula for average atomic mass in your class? It’s here at the very end of the vodcast! Happy calculating on the problems for tonight!

Oh, any questions about the Carbon Isotope Mini-Project?

Image source IBM Almaden Research Center


Physics 12-3-12 Simple Machines

PHYSICS: Happy Monday! Here’s the lecture on simple machines. We’ll add this little bit of chapter 7 to the chapter 5 test. Did you remember this stuff on simple machines from your physical science days?

I don’t think you’ll have any trouble with efficiency and mechanical advantage problems. How do you think the efficiencies of machines compare? Could you design a method to test that? You don’t need no stinkin’ lab sheets! Do you?

UPDATE: I scanned and linked a copy of the last Chapter 5 Review Worksheet for you here – it’s two pages. The questions and problems that are due tomorrow are circled. Chapter 5 Review Worksheet 2

flickr photo by André Banyai


Hon Chemistry 12-3-12 Photoelectric Efffect & Bohr Model of the Atom

HON CHEMISTRY: I figured anybody who ditched his honeymoon to finalize his work on atomic theory deserved to have his picture on our website. (And, by the way, great job making like electrons today – way to role play!)

Here’s a link to a great video clip that begins to show the connection between our lab on spectroscopy, the hydrogen emission spectrum, and how we can identify elements. And don’t forget the watch the other clips from this chapter! They’ll be very helpful as you study!! Spectrum of the Stars

Fun field trip today! Hey what about other applications of the photoelectric effect? Are there tiny people living in boxes above the doors at Wal-mart and Target? What about solar calculators? And hey – what about those automatic flush toilets!

Let me know if you need help with the problems? Don’t give up on the ones tonight! Here’s a hint, see if you can figure out a way to use the speed of light formula and the energy formula together. Bottom line, make sure you not only memorize formulas but be able to think through them to use them. Be careful to learn the symbols and units for each of the quantities you’re going to use, it’s easy to get them confused – and that will help tons. Here’s the lecture from Monday

Image source