# What is the oxidation state of Calcium in teeth?

What is the oxidation state of Calcium found in human teeth?

-
Welcome to Chemistry SE, Kinnard Hockenkull. You can make your question more answerable by telling us what progress you yourself have made in finding the answer to the question. –  Aditya Sriram Dec 30 '12 at 7:53
Ca3(PO4)2 is the compound found in teeth ; the calcium has an oxidation state of 2+ –  LievenB Aug 29 '13 at 13:48

As a group II metal, you will be hard pressed to find calcium in the 1+ oxidation state (a quick google search yields an isolated report of calcium(I) chloride). Calcium's willingness to oxidise is evinced by its vigorous reaction with water. As you have noted, the calcium in tooth enamel is hydroxyapatite, often with varying degrees of fluorination. Which brings me to your next question, which hopefully you or a mod can slipstream into the main body -

I would definitely warn against eating chalk without good reason as it will evolve $\ce{CO2}$ in your tummy and raise your stomach pH, and is associated with a variety of negative health outcomes:

As always, all things in moderation. On a personal note eating chalk sounds like exactly the thing certain sectors of the 'alternative health' crowd would be into (namely, those who assert that the body is 'too acidic' (there's another crowd who claim the opposite and will recommend, say, drinking $\ce{HCl}$ (through a glass straw, natch)), ignoring for a moment the fact that the human body is pretty good at maintaining its pH and will up and have a cardiac arrest or something if the pH drifts more than a bit)

-
+1 (For nesting parentheses (I do it too (Btw, Happy New Year!))) ;-) –  ManishEarth Dec 31 '12 at 16:26
What about gargling? –  Kinnard Hockenhull Jan 1 '13 at 9:50
@KinnardHockenhull - Take it up with an accredited medical professional (which I am not :D) –  Richard Terrett Jan 1 '13 at 10:17
sometimes you have as a result of frequent heartburn and ulcers too little HCl in your stomach and sometimes you have no HCl at all in your stomach. In that case you need to take HCl pills since they are much safer than 1M HCl(aq) –  caters Aug 16 at 21:11