Sunday, December 12, 2010

Household Ions

A. Compound Name
B. Compound Formula 
C. Name of the household item the compound is found in 

   A. Disodium Phosphate
   B. Na2PO4
   C. Betty Crocker Mashed Potatoes: 
   A. Sodium Bisulfite 
   B. NaSO3
   C. Betty Crocker Mashed Potatoes
   A. Sodium Flouride
   B. NaF
   C. Colgate Toothpaste 
   A. Potassium Chloride
   B. KCl 
   C. Orville Redenbacher's Popcorn
   A. Calcium Carbonate 
   B. CaCO3   
   C. Rice Chex Cereal 
   A. Calcium Phosphate 
   B.  CaPO4
   C. Honey Maid Grahm Crackers 
   A. Sugar
   B. C6H12O6
   C. Honey Maid Grahm Crackers 
   A. Sodium Phosphate 
   B. NaPO4
   C. Macaroni & Cheese 
   A. Ferrous Sulfate 
   B. FeSO4
   C. Macaroni & Cheese  
   A. Iron Oxide 
   B. FeO
   C. Milk-Bone Dog Biscuits 
   A. Dicalcium Phosphate  
   B. Ca2PO4  
   C. Milk-Bone Dog Biscuits 
   A. Sodium Chloride 
   B. NaCl
   C. Opti-Free Contact Solution 
   A. Water 
   B. H2O
   C. Febreeze Air Freshener 
   A. Titanium Dioxide 
   B. TiO2
   C. Zyrtec Allergy Pills 
   A. Magnesium Chloride: 
   B. MgCl2
   C. Bedhead Shampoo 
   A. Sodium Nitrate 
   B. NaNO3
   C. Pepperoni
   A. Zinc Oxide 
   B. ZnO
   C. Nutri-grain Bar 
   A. Calcium Hydroxide 
   B. Ca(OH)2    
   C. Orange Juice 
   A. Magnesium Oxide 
   B. MgO 
   C. Peanut-butter 
   A. Ammonium Chloride 
   B. NH4Cl
   C. Bedhead Conditioner

Tuesday, November 9, 2010

FINAL review question #16

How did Thomson determine that the cathode ray was negatively charged?

In 1897, the electron was discovered by an English physicist named J. J. Thomson. An electron is a negatively charged subatomic particle. To discover the electron, Thomson experimented by passing electric currents through gases at low pressures. The gases were sealed in glass tubes that were closed at the ends by two electrodes, or metal disks. The electrodes were connected to a source of electricity. One electrode was positively charged and one electrode was negatively charged. The positively charged electrode was called an anode and the negatively charged electrode was called a cathode. The result of the two electrodes was a cathode ray, or a glowing beam, that traveled from the cathode to the anode. A cathode ray is deflected by a magnet. It is also deflected by electrically charged metal plates. The cathode ray is attracted by the positively charged plats, and is repelled by the negatively charged plate. Thomson knew when conducting this experiment that opposite charges attract and negative charges are repelled from each other. Thomson hypothesized that a cathode ray is a stream of tiny negatively charged particles moving at a high speed. Thomson originally referred to these particles as corpuscles, but they were later renamed as electrons. J. J. Thomson set of an experiment to measure the ratio of the charge of an electron to its mass so he could prove his hypothesis. It was discovered that the ratio was constant and the charge-to-mass ratio of electrons did not depend on the type of gas in the cathode-ray tube or the type of metal used for the electrodes. Thomson was able to conclude from his experiment that electrons must be parts of the atoms of all elements.

Thursday, October 7, 2010

The Discovery of Neutrons

Important Definitions:
Neutron: an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus.  
Electron: an elementary particle with a negative charge equal to the positive charge of an electron.
Proton: an elementary particle with a positive charge equal to the negative charge of an electron.
Quark: any group of six elementary particles having electric charges of a magnitude one-third or two-thirds that of the electron.
Alpha particle: a positively charged particle, indistinguishable from a helium atom nucleus and consisting of two protons and two neutrons.
Isotope: one of two or more atoms with the same atomic number but with different numbers of neutrons.
Beta decay: radioactive decay of an atomic nucleua that is accompanied by the emmision of a beta particle.
Beta particle: a high-speed electron emitted in the decay of a radioactive isotope.
Polonium: a radioactive metallic element that has simillar qualities as bismuth.

What is a Neutron?
A neutron is a tiny suatomic particle that can be found in almost all forms of matter (3). The only stable exception where a neutron is not found is in a hydrogen atom (3).The neutron is located in the atomic nucleus, and it is bound with protons through a strong nuclear force (3). The term "neutron" is used because it has no electrical charge and is therefore neutral (3). A neutron is the result of the combination of a proton and an electron (3). Because a proton has a positive charge equal to the negative charge of an electron, the two are attracted to each other and together they form a neutron (3). Most atoms have an equal number of protons and neutrons in their nucleus (3). However, when this balance is broken, the atom becomes an isotope (3). Neutrons can survive ouside of the nucleus for about 15 minutes, before they undergo beta decay and break down into protons and electrons (3).
Neutrons vs. Protons
Slightly lesser masses than neutrons (2).
Composed of two up quarks and one down quark (2).  
Extremely stable outside the nucleus; takes a long time to decay (2).
Discovered by Ernest Rutherford in 1919 (2).
Used to treat cancer (2).

Slightly greater masses than protons (2).
Composed of two down quarks and one up quark (2).
Extremely unstable outside the nucleus; decay within 15 minutes (2).
Discovered by James Chadwick in 1932 (2).
Used to create weapons of mass destruction (2).

The Discovery of the Neutron
In 1920, Ernest Rutherford had suggested the idea of an electrically neutral particicle when he was trying to explain for isotopes of hydrogen (4). In 1930, Charles Chadwick performed an experiment that would lead to the discovery of neutrons (4). When alpha rays emitted from polonium were fired at light nuclei, the alpha rays gave rise to the penetrating rays and no electric charge could be found (4). The "penetrating rays" were considered gamma rays (4). When a beryllium target was used instead, the rays were even more penetrating than when other targets were used (4). Chadwick was able to conclude that the mysterious radiations did not have any electric charge because it was not affected by how close it was to a magnetic field (5). Gamma radiation involved the photoelectric effect, and these rays did not, so these rays could not possibly be gamma rays (5). The photoelectric effect occurs when protons stike certain surfaces and produce electrons (5). Instead of doing this, the mysterious rays discharged protons (5). This fact also proved that the particles had greate masses than chemists had formerly thought they did (5). In 1931, Chadwick proposed the thought that the neutral rays were concrete evidence of the idea that neutrons existed (4). James Chadwick received the Noble Prize in 1935 for his discovery of the neutron (5).

Affects of the Neutron
The discovery of the neutron changed subatomic physics forever and allowed scientists to discover new elements (4). It also led the discovery of nuclear fission and is used to create nuclear weapons (4). Charles Chadwick was the leader of the British technical team during World War II, and he helped the U.S. invent the atomic bomb (4). The U.S. used this nuclear weapon to attack Hiroshima and Nagasaki, Japan and to defeat Japan in World War II (4).

Characteristics of Neutrons
-Subatomic particles found in nucleus of atoms, along with protons (1).
-No electrical charge (1).
-Mass = 1.6749 X 10 ^-27 kg, or 1,840 times the mass of an electron (1).
-Consists of three quarks: one up quark and two down quarks (1).
-Only stable when bound in atomic nucleus (6).
-Lifetime of free neutron is 886 approximately seconds (6).
-Only neutral to outside; have inner structure with distribution of + and - charges (6).
-Has a spin, or an inner angular momentum (6).
-Can adjust its spin in magnetic field (6).
-Can pass through massive layers with thickness of several centimeters (6).
-Can induce nuclear reactions (6).

Works Cited
(1) Wolfe, Kari. Characteristics of a Neutron. eHow Inc., 1999. Web. 07 Oct. 2010. <>

(2) Weiner, Stephen. Protons vs. Neutrons. eHow Inc., 1999. Web. 07 Oct. 2010. <>

(3) Anissimov, Michael. What is a Neutron? Conjecture Corporation, 1999. Web. 07 Oct. 2010. <>

(4) James Chadwick. Creative Commons Attribution, 2008. Web. 07 Oct. 2010. <>

(5) McPhee, Isaac M. The Discovery of the Neutron. Isaac M. McPhee, 2008. Web. 07 Oct. 2010. <>

(6) Properties of Neutrons. Frank Laboratory of Neutron Physics, 2008. Web. 07 Oct. 2010. <<>

Sunday, September 12, 2010

Physical and Chemical Properties of Marshmallows

     I chose to experiment with the chemical and physical properties of marshmallows because I decided it would be a fun, interesting, and safe experiment. I discovered five chemical properties and six physical properties of marshmallows. I tested four marshmallows for this experiment, and also included a fifth additional marshmallow that I left in it's original condition. First, I microwaved Marshmallow #1 for 30 seconds. The marshmallow expanded to roughly the size of a teacup and much of the marshmallow turned a brownish color. With Marshmallow #2, I placed it in a cup of hot water and after about three hours, it finally dissolved. Next, I put Marshmallow #3 in the freezer for two hours and it completely hardened. When I removed Marshmallow #3 from the freezer, i was able to use a hammer against it about five times before parts of the marshmallow began to crumble. Finally, I used a metal utensil to light Marshmallow #4 on fire. The marshmallow proceeded to turn black and the texture turned rough. The flame shut itself out, but not before the marshmallow had been burned. The chemical properties I observed include: 1) The ability to expand when heated (change in temperature); 2) The ability to change color when heated; 3) The ability to dissolve in hot water; 4) The ability to freeze; and 5) The ability to burn. The physical properties I observed include: 1) Color: white; 2) Density: marshmallow is less dense than water; 3) Conductivity: extremely poor; 4) Attraction to magnets: non-existent; 5) Malleability: slightly malleable when frozen; and 6) Hardness: very soft.

The following is an image containing the results of the experiment: