Quick Blog Question

Oxygen exists as two allotropes: O₂ oxygen gas  O₃ ozone. O₂  makes 20% of the air we breathe. 

O₃ is a gaseous substance found in the upper layers of our planet's atmosphere, as well as in some of the air pollution associated with cities. 

18-21 p. 182, 1-6 p.204

18. The difference between reusing and recycling is that recycling is converting waste into usable material, and reusing is to use more than once.

19. a. renewable resources: solar energy, wind power, tides, hydroelectricity
      b. nonrenewable resources: petroleum, coal, natural gas, nuclear energy


20. a. reusing
      b. recycling
      c. reusing

21. They are both made, packed, shipped, used, disposed, and hopefully recycled.

1. allotrope: two or more forms of an element in the same state that have distinctly different physical and/or chemical properties.

allotropes of carbon

2. oxygen:O₂ oxygen gas  O₃ ozone

   sulfur

allotropes of sulfur

3. a. How their properties are different is because they all contain carbon just in different forms of the element,

    b. Why their properties are different because they have distinctly different atomic arrangements.

    c. What accounts for the differences in the cost of these items are the reactivity, abundance, and need for the item.

4. Engineered materials are more likely to be more stable and sturdier than natural materials because of the other material that they put in it.

5. Two advantages: low chemical reactivity and resistance to wear.

    Two disadvantages; brittleness and they can fracture if exposed to rapid temperatures.

ceramics at a high temperature

6 Two properties that can be modified in plastics to make them useful for new applications are making them safe to be exposed to sunlight and to resist wear and tear. 

Quick Blog Question

A neutron is a particle without electrical charge; found in the nucleus of an atoms, along with a proton, which is a particle possessing a positive electrical charge. An electron is a particle possessing a negative electrical charge; they surround the nuclei of atoms. An atoms consists of a nucleus, protons, and electrons and is the smallest particle possessing the properties of an element. A molecule is the smallest particle of a substance retaining all the properties of that substance. CO₂ and H₂0 are molecules.

13-21 p. 181

13.  a.6 moles
      b. 5 moles
      c. 5 moles

14. a. 1 mole
      b. 621grams
      c. 28 grams
      d. 223 grams

15. The percent oxygen by mass is not 67% because oxygen weighs more.

16. a. 216 + 32= 248   216/248 x 100= 87%
      b. 54 + 48 = 102    54/102 x 100= 53%
      c. 40+12+48= 100  40/100x100= 40%

17. a. 207+32+ 64= 303   207/303x100= 68%
      b. 10%
      c. 6%
   
18. The difference between reusing and recycling is that recycling is converting waste into usable material, and reusing is to use more than once.

19. a. renewable resources: solar energy, wind power, tides, hydroelectricity

      b. nonrenewable resources: petroleum, coal, natural gas, nuclear energy

20. a. reusing
      b. recycling
      c. reusing

recycling plant

21. They are both made, packed, shipped, used, disposed, and hopefully recycled.

Quick Blog Question

My rare Earth metal is yttrium. The largest use of yttrium is in the form of yttrium(Ill) oxide, which is used to produce phosphors which give the red colour in colour television tubes. It is also used in the making of microwave filters, and many other appliences. Yttrium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO₄), a material rich in rare earth elements and bastnaesite by reduction with calcium metal. Yttrium reacts with cold water slowly and with hot water very rapidly. It dissolves in both acids and alkalis. Solid yttrium metal does not react with oxygen in the air.

1-12 p. 180

1. Law of Conservation of Matter: matter is neither created nor destroyed in any chemical reaction or physical change.

2. Scientific Law: summarizes what has been learned by careful observation of nature.

3. They are misleading because "using up"and "throwing away" sound the opposite of the law of conservation of matter, which is that no matter in created nor destroyed. "Using up" means that materials are chemically changed, not destroyed.

4. a. Reactants Sn: 1, H:1, F:1  Products: Sn:1, F: 2, H:2 This equation is not chemically balanced.
   b. Reactants Si: 1, O: 2, C: 1 Products: Si: 1, C: 2, O: 1 This equation is not chemically balanced.
   c. Reactants Al: 1, O: 3, H: 6, Cl: 3 Products: Al: 1, O: 3, H: 6, Cl: 3 This equation is chemically balanced.

5. a. 3
    b. 2
    c. 1

6. a. 1 WO₃ + 3 H₂ ---à 1 W + 3 H₂0
    b. 2 PbS + 3 O₂  ---à 2 PbO + 2 SO₂
    c. 4 Fe + 3 O₂ ---à 2 Fe₂O₃

7. a. 1 Ca₃ (PO₄)₂ + 3H₂SO₄ ---à 2H₃PO₄ + 3CaSO₄
      b. C₈H₁₈ + 13O₂ ---à 8CO₂ + 9H₂0

8. a. Na: 2, S:1, O: 4, K:2, Cl:1---> Na:2, S:1, O: 4, K: 2, Cl: 1
    b. Yes

9. 5

10. a. 32g
      b. 48g
      c. 100g
      d. 58g
      e. 180g

11. They can both represent a mole because a mole is just the amount of an element that you can use in a lab.

12. a. 19 atoms
      b. 9.5 atoms
      c. 1.9 atoms
      d. 1 atom

        

Rare Earth Metals Report by Kourosh, Merry, Ricardo :)

Yttrium 

History: Yttrium was discovered by Johan Gadolin, a Finnish chemist, in 1794 while analyzing the composition of the mineral gadolinite ((Ce, La, Nd, Y)₂FeBe₂Si₂O₁₀) in 1789. Yttrium is named after Ytterby, Sweden. Yttrium is a highly crystalline iron-gray, rare-earth metal.

Johan Gadolin

Uses: 

1. The largest use of yttrium is in the form of yttrium(Ill) oxide, which is used to produce phosphors which give the red colour in colour television tubes. 

2. It is also used in the making of microwave filters. 

3. Yttrium is often used as an additive in alloys, and increases the strength of aluminium and magnesium alloy. 

4. It is also used as a detoxifier for non-ferrous metals. It has been used as a catalyst in ethylene polymerisation.

5. Yttrium-90, a radioactive isotope, has a medical use in needles which have replaced the surgeon’s knife in killing pain-transmitting nerves in the spinal cord.

 phosphors give the red colour in colour television tubes 

Process: Today, yttrium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO₄), a material rich in rare earth elements and bastnaesite by reduction with calcium metal.

Physical Properties: In 1843, Carl Mosander investigated yttrium oxide more thoroughly and found that it consisted of three oxides: yttrium oxide, which was white; terbium oxide, which was yellow; and erbium oxide, which was rose-coloured. It is a silvery metal, which is stable in air because of an oxide film that forms on its surface. 

Atomic number
39
Atomic mass
88.9059 g.mol ^-1
Electronegativity according to Pauling
1.2
Density
4.47 g.cm^-3 at 20°C
Melting point
1500 °C
Boiling point
3336 °C

Chemical Properties: Yttrium reacts with cold water slowly and with hot water very rapidly. It dissolves in both acids and alkalis. Solid yttrium metal does not react with oxygen in the air. However, it reacts very rapidly when in its powdered form. Yttrium powder may react explosively with oxygen at high temperatures.

Neodymium

Name: Greek for "new"

Atomic Number: 60
Atomic Weight: 144.242
Melting Point: 1294 K (1021 C)
Boiling Point: 3347 K (3074 C)
Density: 7.01
Room Temperature State: Solid

Discovery
Neodymium was discovered in 1885 by a researcher named Carl F. Auer. He obtained the rare earth metal through an ion exchange with a common chemical in some rare earth metals, monazite sand.

Physical Properties:
-Bright, silvery look to it
-Very reactive
-Oxidizes in air

Chemical Properties:
-Tarnishes slowly in air
-Very easy to burn
-Reacts slowly in cold water
-Very reactive with all the halogens

Uses: 
Neodymium is used as fertilizer in China. Many compounds of rare earth metals are used in China for fertilization because they promote plant growth, similar to Ca2+. It is also used in samarium-neodymium dating, which is a very exact and useful process for determining the age of rocks and meteors. Another use for the element is in determining the size and strength of a volcanic eruption. By scanning the neodymium isotopes in the volcano, scientists can warn the residents living near the volcano of the intensity of the upcoming eruption.
One of the most common uses for neodymium is in magnets. Neodymium magnets are the strongest permanent magnets known to man, and can lift a thousand times its own weight. They are very cheap to make and fairly light as well, making them better and more useful than the samarium-cobalt magnets. The magnets are used in a multitude of products:
   -microphones
   -speakers
   -in-ear headphones and normal headphones
   -guitar and bass guitar pick-ups
   -hard disks
Neodymium magnet motors were created in 2010, and are now replacing many motors. They are electric, and can be found in hybrid cars and wind turbines.
We know neodymium for its use in iPhone screen color. Neodymium, being highly reactive, reacts with of elements to create the thousands of different colors we see on our iPhone screens.

Occurrence:
Neodymium is not in the least bit rare. The main countries that mine neodymium is China, Australia, Brazil, and the United States. It is estimated that the reserves of neodymium that are still not mined are 8 million tonnes. In the Earths crust, neodymium's abundance is about 10% - 18%. It is the most common rare earth metal, besides cerium present in the earth's crust.

Uranium

Uranium Production:  

World-wide uranium productions amounted to 50,572 tonnes. Kazakhstan, Canada, and Australia are the top three producers and together account for 63% of world uranium production. Other major Uranium Producing Countries are Namibia, Russia, Niger, Uzbekistan, and the United States producing about  1000 tonnes per year are

Uranium Uses

The most common use of Uranium is to power nuclear plants. As of 2008, known uranium ore resources that can be mined at about current costs are estimated to be sufficient to produce fuel for about a century, based on current consumption rates.

Uranium History

The use of uranium in its natural oxide form dates back to at least the year 79 CE, when it was used to add a yellow color to ceramic glazes. Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Bay of Naples, Italy by R. T. Gunther of the University of Oxford in 1912. Starting in the late middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic) and was used as a coloring agent in the local glassmaking industry. In the early 19th century, the world's only known sources of uranium ore were these mines.

Physical/Chemical Properties

Uranium is a hard, dense, malleable, ductile, silver-white, radioactive metal. Uranium metal has very high density. When finely divided, it can react with cold water. In air it is coated by uranium oxide, tarnishing rapidly. It is attacked by steam and acids. Uranium can form solids solutions and intermetallic compounds with many of the metals.

Abundance:

Uranium is very abundant. In fact, the world’s largest known resources increased by 15% in the last two years.