October 15 Homework

Entry for October 15, 2007
Avogadro's Hypothesis

I remember in high school when we were first learning what a hypothesis was. It is actually quite exciting to come up with one and test it to see if it stands to be true or accurate. I enjoy coming up with social hypothesis, discussing them with friends and testing them over time. All done in a very casual manner, but it is fun to think in that way. That being said, I am blown away at the idea of Avogadro or any of the great scientists, mathemeticians and thinkers to come up with these ideas that have become foundations. How exciting it must have been for them! Avogadro didn't even get the chance to know how his ideas became the basis for our mole. Anyway, good to review the definition of a hypothesis versus theory. I have used the term theory in the wrong way and need to substitute "hypothesis" in its place when I am formulating an idea and presenting it to friends.

What is a Mole?

Wow. Just as I would be thinking, "I get this," I would continue to read on and get totally discombobulated. The wording is so dense. I do think I understand the basis on a very elementary level, though. It helped taking as much time as we did in class to discuss the concept of a mole and try plugging it in. The link was a bit dry, too. Those with pictures and examples always help to drive an idea home. As I finished reading this one, I thought that checking back on our class notes might be a better way to review. I thought it was funny how he mentioned that the word "mole" was chosen to confuse science students.

Inert gas of the week:

Helium (He) is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas series in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Extreme conditions are also needed to create the small handful of helium compounds, that are all unstable at standard temperature and pressure. It has a second, rare, stable isotope which is called helium-3. The behavior of liquid helium-4's two fluid phases, helium I and helium II, is important to researchers studying quantum mechanics (in particular the phenomenon of superfluidity) and to those looking at the effects that temperatures near absolute zero have on matter (such as superconductivity).
Helium is the second most abundant and second lightest element in the universe and was one of the elements created in the Big Bang. In the modern universe almost all new helium is created as a result of the nuclear fusion of hydrogen in stars. On Earth it is created by the radioactive decay of much heavier elements (alpha particles are helium nuclei). After its creation, part of it is trapped with natural gas in concentrations up to 7% by volume. It is extracted from the natural gas by a low temperature separation process called fractional distillation.