Contributed by Joe Tilton on Nov 28, 2013
What does it mean? There was preparation the first arrival, so what's the important second arrival?
December 1, 2013
A chemistry professor at a major university tells the story of a young girl who wished to make some potassium hydroxide solution. She decided to throw a large lump of potassium into a bucket of water.
The professor, glancing in her direction, saw what