Re: Introduction To The War in Medicine

In article <47a68e77$0$5630$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Carole <hubbca@xxxxxxxxxxxxxx> wrote:

: Why isn't silica an element?
: Chemistry : Periodic Table : silicon : key information
: This WebElements periodic table page contains key information for the
: element silicon ... silicon oxides such as sand (silica), quartz, rock
: crystal, amethyst, agate, ...
: www.webelements.com/webelements/elements/text/Si/key.html

Reread what you posted and see if you can find the part in which silica
is defined.

: So you're saying that potassium and sodium DON'T burn when exposed to water?

: http://www.lenntech.com/elements-and-water/potassium-and-water.htm
: "In what way and in what form does potassium react with water?
: Potassium reacts rapidly and intensely with water, forming a colourless
: basic potassium hydroxide solution and hydrogen gas, according to the
: following reaction mechanism: 2K (s) + 2H2O (l) -> 2KOH (aq) + H2 (g)
: This is an exothermal reaction and potassium is heated to such an extend
: that it burns a purple flame. Additionally, hydrogen released during the
: reaction strongly reacts with oxygen and ignites."

That is not correct. When potassium contacts water, it liberates hydrogen
and enough energy to set the hydrogen on fire. Because potassium is a
relatively volatile element, a small amount evaporates due to the heat
generated by the reaction with the water. The purple color of the flame
is due to emission of light by electronically excited potassium atoms
returning to the ground state. It is not, repeat not, due to the
potassium burning.

: http://www.lenntech.com/elements-and-water/sodium-and-water.htm
: In what way and in what form does sodium react with water?
: Elementary sodium reacts strongly with water, according to the following
: reaction mechanism: 2Na(s) + 2H2O ? 2NaOH(aq) + H2(g)
: A colourless solution is formed, consisting of strongly alkalic sodium
: hydroxide (caustic soda) and hydrogen gas. This is an exothermic reaction.
: Sodium metal is heated and may ignite and burn with a characteristic orange
: flame. Hydrogen gas released during the burning process reacts strongly with
: oxygen in the air.

This is the same process described above, except that sodium atoms
impart a yellow color to the flame -- it's the same process that gives
sodium lamps their characteristic color. If the sodium in sodium lamps
was burning, the lamps wouldn't last very long.

-----
Richard Schultz schultr@xxxxxxxxxxxxxx
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
Opinions expressed are mine alone, and not those of Bar-Ilan University
-----
"You don't even have a clue about which clue you're missing."
.

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