Week 9:  review of Animations link:   The "Periodic Properties" section is GREAT.  Tells a lot about the history of the Periodic Table, and has good graphics and explains things in an engaging way.... the Acids/Bases/Salts  section was less impressive. Just kind of like reading a boring textbook......except for that one funny picture of a dog drinking out of a toilet, although what that has to do with the subject is questionable.....

My favorite definition of biochemistry was: " Biochemistry is the science that studies the activities of living organisms at the cellular and molecular level".  While all the definitions are technically correct,  this one is specific enough to really define it and give you an idea of what a biochemist might be engaging in.....  A broad statement like "Biochemistry is the chemistry of life" may sound poetic, but it is not helpful to differentiate it from other types of chemistry or biology.......

Week 8:  Semiconductor-- GERMANIUM: Ge: atomic # 32, a shiny hard silver/white metalloid similar to tin. Same crystal structure as diamond. One of the few substances that expands as it freezes!  Was predicted by Mendeleev, but was proved to exist by Clemens Winkler in 1886.

It is a semiconductor material used in transistors. It was used in "solid state" electronics from the 1950's until the 1970's, then silicon became more commonly used.  Solid state components have no mechanical action , but electromagnetic action instead. I always wondered what that meant.

Week 8:  Chembalancer and Balancing Equations Tutorial were both useful for practicing and getting it down.... I'm going to save all of these for when my son is a little older and learning chemistry....The website about the acidity and alkalinity of various foods is my FAVORITE website we have looked at, and I've emailed it to many of my clients and friends. Very useful.

week 7:   RADON!   one of the 6 "Noble Gasses" , which used to be called rare gasses, but Argon is not so rare, and "inert gas" is a misnomer too since several do take part in chemical reactions.

Rn : atomic # 86, #neutrons=136, has 6 energy levels. Colorless, odorless gas with a cubic crystal structure. Discovered in 1898 by Freidrich Ernst Dorn. It's a radioactive gas that emanates from radium compounds, i.e. is obtained from a radium chloride source (the kind used in cancer treatment anyway). Radium and radon are not used in x-ray medical radiography like they used to be.... it is also produced during the operation of nuclear power plants. It is probably what killed Marie Curie in the end.....

Radon is a contaminant of indoor air that causes 21,000 LUNG cancer deaths in the US per year, the second leading cause of lung cancer after cigarettes. It can accumulate in buildings from natural sources beneath them-- soil and rock!    AAAAACK!

Week 7:    So, unfortunately Avogadro never got any credit in his lifetime for having the radical thought to make a clear distinction between atoms and molecules. Poor guy.  This is a good website for explaining things about the scientific process..... A good definition of a HYPOTHESIS: merely a tentative explanation of observed events, not a prediction, but it allows you to make predictions that can be tested by experiments (and may eventually become accepted as scientific theory).  Avogadro's number (6.02 x 10 to the 23rd, ) is the number of fundamental particles in a mole of substance.  Gram molecular weight is a convenient weight..... a gram molecular weight of any substance contains (Avogadro's number) of molecules.....a particular volume of gas is proportional to molecular weight.  A MOLE is a gram molecular weight of a gas (at standard temp. and pressure), it occupies 22.4 liters of volume. Another way to say it is: 22.4 liters of a gas (at standard temp and pressure) contain the number of molecules that weigh as much as the molecular weight of the gas expressed in grams.

I think these were good websites..... I would need to hammer it into my brain a lot longer to make it stick though.  

Week 6--- Alchemy: Historically an attempt to understand the cosmos... leading to scientific discoveries in chemistry, physics......, some  misguided attempts to use magic to achieve certain goals (making gold out of other things,  achieving immortal life through various means)  , Historical Chinese Taoist "external alchemy"-the search for herbs of immortality- led to some practical herbal medicine....(and lots of death by mercury ingestion) .... "internal alchemy" in which the alchemist overcomes the limits of individuality and gains transcendental knowledge... has enduring relevance for anyone interested in meditation, energetics, philosophy/spirituality or achieving a higher state of being....TCM is an "alchemical" art in the sense that it combines energetic manipulation and herbal elixirs, etc.

So yes, alchemy is or has been science, art, and magic....

 The halogen of the week: Fluorine. Symbol is F. Atomic number is 9. It is the element for which the largest number of atoms combine with atoms of other elements..."univalent"....it readily forms compounds with most other elements...It is the most chemically reactive and electronegative of all the elements. 

In pure form it is a poisonous pale yellow/brown gas. Like the other halogens , contact with skin gives you severe chemical burns. It is a powerful oxidizing agent and reacts EXPLOSIVELY with hydrogen. It is too reactive to be found in elemental form.

Fluorides are compounds that combine fluorine with some positively charged counterpart.

--atomic fluorine is used in semi-conductor manufacturing

--sodium fluoride compound and others are used in toothpaste and water fluoridation,  more        about that controversy later....

--SSRI anti-depressants are fluorinated molecules! And because our bodies have difficulties metabolizing fluorinated molecules, these are the major cause of fluorinated organics found in sewage and waste water!

--Fluorochlorohydrocarbons are used in air conditioning and refrigeration. CFC's, or chlorofluorocarbons, are banned due to ozone destruction, but it is the chlorine and bromine radicals which are the guilty parties, not fluorine, thus hydrofluorocarbons are not banned by the EPA. They have a relatively small greenhouse effect compared to CO2 and methane.