Friday, May 13, 2011

Test Review #1, a-u

a. an electron in the highest occupied energy level of an atom
valence electrons
b. shapes adjust so valence-electron pairs are as far as possible 
VSPER Theory
c. indicator changes colors
end point
d. attraction between polar molecules
dipole interaction
e. solution containing more solute than can theoretically dissolve at a given temperature
saturated solution
f.  a reaction in which a single compound is broken into simpler substances
decomposition
g. the mass of a mole of any element or compound
molar mass
h. covalent bond in which only one pair of electrons is shared
single bond
i. covalent bonds occur between two of these
atoms
j. particle emitted when a nucleus transforms a proton into a neutron
positron
k. rule explaining why atoms react so as to acquire the stable electron structure of a noble gas
octet rule
l. the percent by mass of each element in a compound
percent composition
m. this is conserved in every ordinary chemical reaction
mass
n. acid with two ionizable protons
diprotic acid
o. the reactant that is not completely used up in a reaction
excess reactant
p. the reactant that determines the amount of product that can be formed in a reaction
limiting reagent
q. increases when a solute is added to a solvent to form a solution
boiling point
r. bonding formed by the attraction of valence electrons for metal ions
ionic bonding
s. the volume occupied by a mole of any gas at STP
22.4 L
t. occurs when an unstable nucleus divides into two nuclei of roughly equal mass
nuclear fission
u. a reaction in which oxygen in limited supply reacts with another substance often producing heat or light
chemical reaction

Monday, April 4, 2011

Nuclear Disaster

Site 1
How Nuclear Power Plants Work:
Site 2
(Site 2) In order to understand the effects, and benefits of nuclear plants, we have to know what goes on inside of them. The Core contains hundreds of Fuel Rods stacked with Uranium. To control the fission process, the rods known as "control rods," are raised and lowered to absorb neutrons. These are then surrounded by water known as the Moderator. The purpose of this water is to slow the neutrons so they are easily and effectively used. Then coolant is used to cool the reactor core. This water when heated is then used to produce steam and is recycled. This spins a turbine which produces electricity, then the steam is condensed back into cooler water.
History of Chernobyl:
(Site 3) Chernobyl was built in the marshlands of Northern Ukraine. All four reactors were built in the time range of 1977-1983. On April 25th, 1986, the fourth reactor was closed for maintenance to make sure it was producing enough energy to provide the city with power in case of an outage. When the tests were running, they also shut off a few of the safety systems. On April 26th, the power dropped and the reactor went out of control. Nobody outside of the plant knew, until two days later the operators of Forsmark, a Swedish plant, contacted Chernobyl because of high radiation levels measured near that plant. The Soviet Union denied any knowledge of a disaster, until April 28th when they said "one of the reactors had been damaged."
Chernobyl Reactor 4
Site 6
What went wrong at Chernobyl:
(Site 4) Much of the reason for the incident at Chernobyl was the ignorance of the workers to comply with the safety measures that were supposed to be taken. The Uranium fuel overheated and melted through the protective barriers. (Site 5) Also, the engineers that were staffing the nuclear reactor were specialists in electrical reactors, not nuclear. 

Chernobyl today
(Site 7)
What was done to remedy the situation:
(Site 3) The Soviets were trying to keep the disaster a secret but attempting to clean it up at the same time. At first, they tried to put the fires out by using water, sand, lead, and nitrogen. The fires burned for more than two weeks. Radiated soil and water were contained and the reactor was encased in cement. A new containment is set to be finished in 2013

What are some of the lasting effects today:
(Site 4) It is safe to visit the area today because the radioactive isotopes that still linger, are so small that they are tolerable for a short period of time. People have moved back to Chernobyl.
(Site 8) 28 of the firefighters at Chernobyl died within 3 months of the incident, and others died later from lasting effects. (Site 9) The radiation released was 400 times greater than that of Hiroshima. Over 300,000 people were resettled because of this catastrophe. Although radiation has increased, it has been reported that there has been more wildlife growth in this area (partially because of lack of human influence).

How does Chernobyl compare with Fukushima (Japan):
(Site 10) Chernobyl was the only radioactive disaster ever recorded at a level 7/10. The recent disaster in Japan has been upgraded to a level 5. Chernobyl was not prepared for the disaster that they faced, and were not aware of the consequences they would face. They did not begin evacuation until almost two days following the explosion, as opposed to Japan which began immediately. The Chernobyl disaster was caused by human carelessness, when the Japan incident was caused by natural disaster. (Site 11) Because graphite was used in Chernobyl, it caused a much bigger radiation "cloud," pushing the radiation higher into the atmosphere.

Should we be worried about the Japan incidents?:
(Site 11) Although radiation will travel across the United States, and most of the world at some point, it will be so small that it won't have any effect on the human body, or our everyday lives. (Site 13) Much of our products come from Japan such as seafood or clothing, but it is not believed that it will harm products from Japan. Scientists are monitoring the radioactive levels in case of a spike in radiation.


Sources:

9.     h

13. .http://www.myfoxhouston.com/dpp/news/local/110315-japans-nuclear-crisis-should-we-be-worried-here


Friday, December 10, 2010

Household Ions





Fiber One Pop-Tarts:

  1. Ammonium Bicarbonate- NH4HCO3
Bowl Noodles:
  1. Potassium Carbonate- K2CO3
Cliff Bar:
  1. Magnesium Oxide- MgO
  2. Potassium Oxide- K2O
  3. Chromium (II) Chloride- CrCl2
Mac-n-Cheese:
  1. Iron (II) Sulfate- FeSO4
  2. Calcium Phosphate- Ca3(PO4)2
Dove Shampoo:
  1. Sodium Chlorite- NaClO2
  2. Sodium Sulfate- Na2SO4
Golden Grahams:
  1. Sugar- C6H12O6
Chicken Noodle Soup:
  1. Sodium Phosphate- Na3PO4
Nuun Active Hydration:
  1. Sodium Bicarbonate- NaHCO3
  2. Potassium Bicarbonate- KHCO3
  3. Sodium Carbonate- Na2CO3
  4. Magnesium Sulfate- MgSO4
  5. Calcium Carbonate- CaCO3
Power Bar Gel:
  1. Water- H2O
  2. Potassium Chloride- KCl
  3. Sodium Chloride- NaCl
Proactiv:
  1. Sodium Hydroxide- NaOH

Wednesday, November 10, 2010

Review #30

Just making sure we covered everything, I chose Dimensional Analysis because we covered it so early some of us may have forgotten it by now. Here are some questions you can try out and the answers are listed at the bottom.

Here are the conversions you will need:
1 miles= 5280 ft.

1 inch= 2.54 cm.
1 lightyear= 9.467x10^15m
1 parsec= 1.91738x10^13 mi.


1) 5.0 in = __ mm
2) 123.0 ng= __ Mg
3) How many parsecs make up a lightyear?

Key:
1) 127
5in. x 2.54cm/1 in. x 1m/100cm x 1000mm/1m

2)1.230x10^-13
123.0ng x 1g/10^9ng x 10^-6Mg/1g

3) 0.3068
9.467x10^15m x 100cm/1m x 1in./2.54cm. x 1ft./12in. x 1mi./5280ft. x 1 parsec/1.91738x10^13

Tuesday, October 5, 2010

Chapter 4: Discovery of Protons

Who?
Ernest Rutherford,a British chemist, was known as the father of nuclear physics. He worked with nuclear physics and experimented with the nucleus and different kinds of atoms.
What?
The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom, along with neutrons, but is also stable by itself and has a second identity as the hydrogen ion, H+. It is composed of three fundamental particles: two up quarks and one down quark.

The Experiment:
After the discovery of the electron in 1897, scientists realized that there must be a positive charge.  He then shot alpha particles through nitrogen gas and observed the charge of the particles that passed through the foil. Any other particles that passed through would fall onto the zinc sulfide screen and create a sparkle. These were all shown to have the same positive change as a proton. Some even came back towards the way they had come from. This showed him that there were even protons in the nucleus because the protons would bounce back off the other protons.

Why he chose this?
In 1919 Rutherford discovered that he could change one element into another by striking it with energetic alpha particles. Rutherford conducted numerous experiments and in every case, hydrogen nuclei were emitted in the process. He saw that the hydrogen nucleus was important to the atomic structure and by 1920, scientists reffered to it as "a proton."

Nuclear transmittion taking place.


"Rutherford bombarded gases with alpha particles."



Bibliography:
1. Sawyer/ Assist. Professor of Physics, Louisiana Tech Univ., Dr. Lee. "Who Discovered the Proton? And How Was It Discovered?" Physics and Astronomy Links - PhysLink.com. Web. 05 Oct. 2010. http://www.physlink.com/education/askexperts/ae46.cfm.
2. "Discovery of Protons." Oracle ThinkQuest Library. 1999 ThinkQuest Team. Web. 05 Oct. 2010. <http://library.thinkquest.org/27954/proton.html>.
3. "Ernest Rutherford." Wikipedia, the Free Encyclopedia. Web. 05 Oct. 2010. http://en.wikipedia.org/wiki/Ernest_Rutherford.
4. "Proton." Wikipedia, the Free Encyclopedia. Web. 05 Oct. 2010. http://en.wikipedia.org/wiki/Proton.
5. "YouTube - Rutherford's Experiment: Nuclear Atom." YouTube - Broadcast Yourself. Web. 05 Oct. 2010. <http://www.youtube.com/watch?v=5pZj0u_XMbc&feature=related>.

Friday, September 10, 2010

The Chemical and Physical Properties of Bread

I chose to use bread for my project because I thought since it was made of flour, it would react to a lot of different things.

Materials:
5 pieces of bread
Hammer
Water
Freezer/Ice Cubes
Knife
Water/Pot
Liquid-Plumber gel

Clorox bleach
Suave Hair Spray
4 Glass Cups
Matches
3 Pieces of Bread
Sally Hansen Nail Polish Remover

Physical Properties: 
Property of a compound that can change without involving a change in chemical composition; examples are the melting point and boiling point

1) My first physical property was the ability of the bread to be cut. Because the bread is soft, it is easily split into many pieces.

2) My second tested physical property was freezing. I put the bread into a bowl of ice in the freezer and let it sit for about 25 minutes. I tested for progress along the way and the bread had turned solid relatively quickly. When I pulled it out, it was not bendable, and could've been broken in half like a cracker. This did not change the state of the bread which still made it a physical property.

3) My third physical property was hammering the bread. It was easily crushed because of the soft material that the bread is made with. After hammering the whole piece just once, the entire piece of bread was as flat as a piece of paper.

4) My fourth physical property was soaking the piece of bread in a bowl of water. I did this for about 20 minutes, and by the end when I took it out, the bread was soggy and had absorbed the water. It had absorbed so much water that the bread was falling into pieces. 

5) My fifth and final physical property was boiling the water on the kitchen stove. I left the bread in for about 20 minutes, and by the end the bread had puffed up and was full of water. There was a temperature change but only because the water inside of the bread was hot. 



__________________________________________________________________

Chemical Properties: A
 property used to characterize materials in reactions that change their identity.





1) My first chemical experiment was using nail polish remover to soak the bread in. At first there was a reaction, and the bread started bubbling, but from then on the bread just soaked in the nail polish remover. The pink color was absorbed into the bread, and there was a scent from the original liquid, but other than that there were no serious reactions to the remover.

2) The second test I did was soaking the bread in Clorox bleach. There wasn't an immediate reaction but after about 10 minutes there was a foaming on the top of the cup and the bread was still there, but soggy. After about 20 minutes there was a yellowish tint to the bread that wasn't initially there, and after 30 minutes, the bread had completely dissolved and there were no remains left. This was an apparent chemical reaction because of color change, dissolving, and foaming.

3) The third chemical test I did was lighting the bread on fire. It was not easy, and at the beginning the bread wouldn't catch fire. After about 20 minutes of trying, the top layer of the bread had burned and been crusted over with a black layer. There was an obvious odor coming from the burning, and the color change that you look for in a chemical change. 

4) Another test I did was used liquid plumbing gel mixed with the bread. After about 10 minutes there was a strong odor, and brown coloring showing on the bread. The bread had also started to inflate, and the color continued to change. There were also small holes in the bread from what seemed to be the beginning of it dissolving. After about 30 minutes, there were little remains of the bread, and the color had changed to a more tan like solution.

5) The last chemical property that I tried on the bread was hair spray. I thought this would be a good idea because there might be a bubbling from a reaction on the surface. After coating the bread in a few layers of hairspray, I waited for about 40 minutes and there was no change at all. When I picked up the bread, it was hard but not crunchy, and there were no signs of color change or any type of dissolving or bubbling. 

Overall, the experiment was successful. I found that bread only reacts to a limited amount of products, even though it is made of such a reactant material. The physical properties outnumber those of the chemical properties because bread is such an easily manipulated item.