Saturday, August 22, 2009

Alkaline Earth Metals



As a continuation of the periodic table series, this post will cover the second group of elements in the periodic table, the alkaline earth metals:
  • Beryllium, Be
  • Magnesium, Mg
  • Calcium, Ca
  • Strontium, Sr
  • Barium, Ba
  • Radium, Ra
These elements are described as "alkaline" earth metals because they form metal oxides with oxygen, which produce "alkaline" AKA basic (pH > 7) solutions when dissolved in water. One similarity among them is that they all have two electrons in their outermost shell of electrons (the ones that typically participate in chemical reactions). Consequently, they tend to ionize to a +2 cation and form salts with halogens and water, e.g., MgCl2, Ca(OH)2, etc.

Two of the alkaline earth metals are present in human bodies. Can you guess which ones?

Definitely NOT radium (it's radioactive!). Definitely not beryllium (toxic...). The two most prevalent group II elements in our bodies are magnesium and calcium. Think bones and ion pumps and enzyme cofactors...

Now, for the mnemonic:

Beryllium Metal Compounds Should Be Respected.

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