Week 7

Humanities:

This week we looked at different dams and how their impact on the environment. I was extremely dissapointed when I found out just how much humans in populated cites are destroying beautiful, and vital life sustaining. Owen's Valley is a sad example of the misuse of water. When the city of Los Angles started to grow rapidly, they county built an aqueduct from Owen's Lake. As the population, so did the amount of water needed, which started to dry out. When Los Angles started stealing it's groundwater as well, the shrubs and native bushes dried up. This caused many dust storms, which made it impossible to use the Highway. It is currently a some what of a dry lake, but there are efforts to restore it by flowing water there. For many birds, Owen's lake is an important stopover place. Now, again with the restoration efforts, more and more birds are starting to appear at Owen's lake.

Water rights and more:

Los Angles bought the property around Owen's Valley along with water rights. Which means that Los Angles owns the water as well as the land there. After they acquired the water and most of the valley from farmers, they started to divert the water into the city to supply the people there. Since Los Angles owned that area, they exploited it. After many protests, LA has finally decided to let water flow to the river.

This is a possible future for Hetch Hetchy if nothing is done. Hetch Hetchy is a dam near Yosemite National Park. Since this Dam has been up and running for a while (and it would take work to restore it), San Francisco is reluctant to change its ways. The only reason San Francisco has these rights is because it is a big, rich city.

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Chemistry:

Hydrogen Balloons:

This Monday, my class made Hydrogen balloons by mixing citric acid and magnesium in water. This was done in a volumetric flask with a balloon on the top. The balloon filled up gas as the reaction took place. The flask also heated up. Then the balloon was set on fire. It made a loud noises when the balloon finally caught on fire.

Questions and Science:

1. Why did the flask heat up?

The flask heated up because the Magnesium was forming a more stable bond with the citrate ion. When the strong bonds are broken, the reaction releases energy, which is felt as heat.

2. What is fire?

Fire is energy. When energy is absorbed by an atom, the electron moves up an energy level (or two ... or more) and when the electron moves down, it releases energy. This energy is released as heat and light (fire).

3. Why did the balloon float?

The balloon is filled with diatomic Hydrogen molecule. Since hydrogen has a lower density than most of the air, the balloon floats.