Homework #10

1. Because infrared radiation is mostly heat energy, exposure to it is not as harmful as exposure to ultraviolet light, which is the most energetic form of sun radiation. Ultraviolet light can cause sunburns and skin cancer and can even sterilize materials by killing bacteria and destroying viruses (UV-C radiation).


2. Visible solar radiation provides the energy needed for photosynthesis and the visible scattering of light during sunset. 


3. Since there is less water vapor, and therefore, less greenhouse gas caused by water vapor in dry and arid regions such as New Mexico and Arizona, infrared radiation is not as stored and reradiated and reflected back into the atmosphere from the entering of UV and visible light that is transformed into IR radiation in clouds, but the visible and UV radiation directly exposed to the surface of the earth  is used to heat earth. This results in wider air-temperature fluctuations from night to day than states with more humid conditions, for not as much heat is stored in the clouds.


4. 
a. The daytime temperatures would be much cooler, because with less greenhouse gases, less infrared radiation would be stored and reradiated and reflected back into the atmosphere from the transformation of UV and visible radiation to IR radiation in clouds. Less stored heat energy would enter throughout the day.
b. Without stored heat energy in the atmosphere, nights would be very cold without the presence of the sun.

pg. 350

1. The mass of carbon dioxide produced daily by all 10 Riverwood High School buses is 1 kg.

2. 0.40 L of fuel are consumed daily by buses idling at Riverwood High School.

3. In a 180-day school year, 180 kg of carbon dioxide would be released into the atmosphere by these buses while idling. 72 L of fuel would be consumed.

4. Atmospheric CO2 levels have increased by about 30% since 1800 due to clearing forests, combustion of cuttings and scrap timber, and the burning of fossil fuels.

5. No, because enough fossil fuel gas is produced naturally on its own.

6. The school bus-idling policy may seem necessary to some people in order to preserve the atmosphere and prevent pollution.

pg. 233

1. A hydrocarbon is a molecular compound that only contains atoms of hydrogen and carbon.

2. Petroleum is not only a nonrenewable resource, but a very versatile material that is used both as fuel that can be converted to gasoline; therefore, it can be used as heat sources, can deliver energy to generate electricity, can generate energy, and is also used to produce useful every day products, it is a valuable resource.


3. Oil is crude because it is pumped from underground and using it in a natural state without some degree of refinement where it is separated into simpler mixtures is not possible (through fractional distillation).


6.
a. 2,200,000 barrels
b. 17,800,000 barrels


7. Heating and cooking fuel, petrochemicals, kerosene, diesel fuel oil, lubricating oil and grease, heavy oils and wax, petroleum jelly, road oils and asphalt, petroleum coke.


8.
a. Water bottle, sports equipment, clothing, artificial limbs.
b. A water bottle can be made out of aluminum, bamboo can be used to make light, flexible, and durable sports equipment, clothing can be made of cotton, and artificial limbs can be made of iron (although it is much better to make them out of plastic).


10.
a. The Middle East has the most petroleum reserves relative to its population.
b. Central Asia, Far East, and Oceania have the least petroleum reserves relative to its population.


11.
a. North America, Central Asia, Far East, and Oceania, Western Europe, and Eastern Europe consume a greater proportion of the world’s supply of petroleum than they possess.
b. The Middle East, Africa, and Central and South America consume a smaller proportion of the world’s supply of petroleum than they possess.


12. Density can be used to separate two different liquids if the substances are insoluble with each other.


13. Water and acetone would be the easiest to separate from each other by distillation. This is because since water has the highest boiling point, and acetone has the lowest of the four substances, water and acetone would separate fairly quickly and easily by distillation.

15)  

16. Fractional distillation does not separate each compound in crude oil, but produces several distinctive mixtures, called fractions. Fractional distillation is also a continuous process. The crude oil is heated in a furnace and then pumped into the fractionating tower. The temperature within the tower (distilling column) is highest at the bottom and decreases towards the top. Smaller and lighter molecules that have lower boiling points vaporize to the top of the tower, and fractions with larger molecules with higher boiling points condense back to liquid in trays in the lower part of the column. Substances with the highest boiling points never vaporize, but drain from the base—bottoms.

17. 

Light: Aviation gasoline and motor gasoline, kerosene, and refined oils.
Intermediate: Gas oil, petrochemicals, heavy furnace oil, and diesel fuel oil.
Heavy: Lubricating oil and grease, heavy oils and wax, and cracking stock.


18. The fraction with the highest boiling point range would be removed at the bottom. This is because they are thick (viscous) liquids that never vaporize, called bottoms; they drain from the tower’s base.


19. A way to further separate the components of each fraction would be through distillation after a fractional distillation.


20. Methane (CH4), pentane (C5H12), hexane (C6H14), octane (C8H18).
The boiling points increase with greater amounts carbon atoms within the straight-chains of hydrocarbons; the higher the boiling point, the stronger the intermolecular forces are between the molecules.

21. A covalent bond is the sharing of two or more valence electrons between two atoms, allowing both atoms to fill their outer shells completely.

22. Atoms with filled electrons (8 valence electrons) are particularly stable, and therefore, tend to be chemically uncreative. Noble gases are atoms with filled outer electron shells.


23. Since the two dogs desire the sock, they must share it, although they desire to have it for themselves; like repelling electrons, the dogs pull away from each other, but are still connected by the bond they share with the sock connecting them.

26.
a. A structural formula shows the makeup of a molecule, as well as how high the boiling point is, where as a molecular formula just shows the amount of atoms each element in the formula possesses.
b. The structure of a formula shows how strong molecular bonds within the formula is, as well as the boiling point of the formula.

27. See drawings


28. The electron-dot representation of a carbon atom only shows four dots because the four dots represent the valence electrons, located on the outer (and not inner) shell of the atom, where two electrons are located.

29.
a. C9H20
b. C16H34
c. C10H22
d. C18H38

30.
a. 128g
b. 226g
c. 142g
d. 254g

Homework #9

1. The frequency of electromagnetic radiation and energy are the same. 

2. The word spectrum means a vast range.

3. Visible light is useful in plant photosynthesis while other forms of electromagnetic radiation are not because visible radiation can supply energy needed for the reactions by energizing electrons in chemical bonds.

4 a. Infrared, visible, ultraviolet b. Infrared radiation affects living things because it is essentially heat energy, which provides warmth. Visible radiation affects living things through photosynthesis because it can energize electrons in chemical bonds. Although ultraviolet radiation can cause sunburns, skin cancer, and can kill bacteria and destroy viruses, it can affect living things in a positive way because some exposure fuels production of Vitamin D.

5. Ultraviolet light is effective for the use of sterilizing lab protective goggles because UV-C radiation can kill bacteria and destroy viruses, unlike visible light.

6. Infrared radiation is absorbed by carbon dioxide and water vapor, and the energy is then projected back to earth. The majority of visible radiation directed towards earth travels to Earth's surface on a clear day. UV-C radiation is absorbed in the stratosphere before reaching earth's surface and most UV-A and UV-B radiation is absorbed by the stratospheric ozone layer.

7. The more greenhouse gases produced, the more infrared radiation is absorbed. There is then more energy on earth’s surface, hotter water, and a much hotter planet.

8. a. Asphalt warms up more quickly when exposed to sunlight because right when solar radiation makes contact, it is reflected back into space. Lake water does reflect light, but also absorbs and stores heat. b. Water may act like greenhouse gases and absorb infrared light. Asphalts directly reflect light sources back into space.

14. Atmospheric CO2 and water vapor help maintain moderate temperatures on Earth's surface because CO2 blocks out the infrared light, sustaining the correct amounts of UV visible light entering Earth.

15. a. Natural processes: decay of plants/animals, absorption of CO2 -- Human activities: burning fossil fuels, bonfires b. Natural processes: plants decay, cows let out methane -- Human activities: bonfires, methane

16. Temperature increase: methane and CO2 increase. Temperature decrease: ozone increase and solar energy decrease

17. This is because infrared radiation can't leave the greenhouse.

18. 

• a. 
  

• b. 

19. Three chemical reservoirs of carbon atoms are limestone, fossil fuels, and plant decay.

20. This is because the carbon atom can be recycled and become apart of many different parts of the earth. 

Homework #8

#7-13 (p.204)

7)  An alloy is a solid combination of atoms of two or more metals. 

8) Some of my jewelry is made of gold and steel is used all around the house in plumbing. 


9) Carbon, C, is a component of both steel and stainless steel. 

10)
Chromium-platinum alloy: 
Formula: Cr3Pt
Use: basis of some commercial razor blade edges. 
Physical property: very hard

11) Elements that behave as semiconductors are located on the break between metals and nonmetals--metalloids. 

12)Four elements commonly used for doping semiconductors include phosphorus (P), arsenic (Ar), aluminum (Al), and gallium (Ga). 

13) The primary use of the products of semiconductor technology is the allowance for computers to process digital information. 

Homework #7

#1-6 (p.204)

1. Allotropes are different forms of an element that each have distinctly different physical or chemical properties. 
2. Oxygen and silicon are allotropes.
3. a. The properties of graphite are that is it black, a conductor, and leaves a black mark on paper. The diamond is colorless, glass-like, and is very hard. The coal is powdery, and round. b. They can all be different because they have different atomic arrangements. c. The prices are based on the rarity of the atomic arrangements. 
4. Engineered materials are processed while natural materials remain untouched.
5. Ceramics have low reactivity and have durability at high temperatures. The disadvantage is that ceramics are brittle. 
6. Polyethylene can be tailored to be soft and pliable. Optical fibers can replace copper wires in phone data transmutation lines. 
   

Homework #6

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

14. a. 2 moles
      b. 621 grams
      c. 28 grams
      d. 415 grams

15. The actual mass is 66.6666666% but rounded it is 67%.

16. a. 87%
      b. 53%
      c. 40%

17. a. 68%
      b. 10%
      c. 6.8%
      d.






18. a. Reusing is when something is used more than once. Recycling is when you convert an object into a new object.
      b. Reusing: water bottles, paper
          Recycling: cans, glass, plastic

19. a. water, fertilizer, air, soil
      b. gold, silver, minerals, fossil fuels

20. a. reusing
      b. recycling
      c. reusing

21. The newspaper can be refused and recycled while the glass cannot.

Homework #5

1) The law of conservation of matter is that matter is neither created nor destroyed.

2) Scientific law summarizes what has been learned by careful observation of nature.

3) These expressions can be misleading because, according to the conservation of matter, atoms are never 'used up' or 'thrown away'.

4) 
a. Not balanced.
Reactant side: Sn: 1, H: 1, F: 1
Product side: Sn: 1,  H: 2, F: 2
b. Not balanced. 
Reactant side: Si: 1, O: 2, C: 1
Product side: Si: 1, O: 1, C: 2
c. Balanced. 
Reactant side: Al: 1, O: 3, H: 6, Cl: 3
Product side: Al: 1, O: 3, H: 6, Cl: 3
5) 
a. The coefficient for hydrogen gas is 3.
b. The coefficient for NH3 gas is 2. 
c. The coefficient for nitrogen gas is 1. 

6) 
a. 1 WO3 + 3 H2 --> 1 W + 3 H2O
b. 2 PbS + 3 O2 --> 2 PbO + 2 SO2
c. 4 Fe + 3 O2 --> 2 Fe2O3

7) 
a. 1 Ca3(PO4)2 + 3 H2SO4 --> 2 H3PO4 + 3 CaSO4
b. 2 C8H18 + 25 O2 --> 16 CO2 + 18 H2O

8) 
a. Yes. 
Reactant side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
Product side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
b. No, when balancing equations, subscripts remain the same, but coefficients are altered to balance the equation. 
c. 1 Na2SO4 + 2 KCl --> 2 NaCl + 1 K2SO4

9)  It would take 400,000 seconds to spend one mole of dollars.

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

11) This is because a mol is a unit of measure. 

12) 
a. 1 atom.
b. 0.5 atoms. 
c. 0.1 atoms. 
d. about 0.03 atoms.

Homework #4

#9-22 (p.151)

9) Active metals are more reactive than less active metals. Active metals are more likely to combine and form compounds with other elements which makes them more difficult to process and refine.

10)

11)  This is because metals are reactive and combine with other elements.


12) A reaction between calcium metal with chromium(III) chloride would more likely occur because calcium metal is more reactive than chromium metal.

13)  Zinc in a silver solution would cause a reaction because the more reactive material is in a less reactive solution.

14)

a. This is because the spoon would cause a reaction.
b. Pb^2+(aq) + Fe(s) ---> Pb(s) + Fe^2(aq)

15) Oxidation is the loss of one or more electrons that causes a metal to become a cation/aqueous solution. Reduction is the gain of one or more electrons that causes a cation/aqueous solution to balance its electrical charge and become a metal.

16)
a. Au^3+ + 3e^- ---> Au
b. V ---> V^4+ + 4e^-
c. Cu+ ---> Cu^2+ + 1e^-

17)
a. reduction.
b. oxidation.
c. reduction.

18)

a. Zinc
b. Nickel
c. Zinc

19)
a. Potassium
b. Mercury
c. Mercury

20)
a. Al + Cr^3+ ---> Al^3+ + Cr
b. Mn^2+ + Mg ---> Mn + Mg^2+

21)
a. Electrometallurgy is the use of electricity.
b. Pyrometallurgy is the use of heat.
c. Hydrometallurgy is the use of water.

22)
a. Electrometallurgy.
b. Pyrometallurgy

Homework #3

#26-34 (p.132)
26. Nonmetallic elements are more likely to loose electrons.
27. This indicates that noble gasses are nonreactive and very stable. 
28. a. cation, b. cation, c. anion, d. anion, e. anion, f. cation, g. cation, h. anion
29. A. Copper metal and copper(II) are more similar because the only difference between them are electrons.
30. The diameter would be 206 pm.
31.

• a. Change in color
• Chemical: rusting
• Physical: paint
• b. Change in temperature
• Chemical: burning
• Physical: boiling
• c. Formation of a gas
• Chemical: reaction of 2 elements
• Physical: evaporation

32.

• a. Bromine
• b. Silicon

33. Mendeleev organized the periodic table by atomic weight and in the fish kill we had to figure out the substances  that caused the fish to die by measuring the amounts of substances. 
34. Argon and potassium would be in different places if the periodic table was organized by atomic weight as well as cobalt and nickel. 
#1-8 (p. 151)
1. 

• Atmosphere: nitrogen and oxygen
• Hydrosphere: water and dissolved minerals
• Lithosphere: petroleum and metal-bearing ores

2.  a. The crust: top 40km: the thin band of soil and rock containing major raw materials needed to build all manufactured objects. 
The mantle: 40-2900km: the middle layer of the lithosphere. 
The core: 2900km: Earth's center: extremely hot.
b. The crust serves as the main storehouse of chemical resources used in manufacturing consumer products. 3.
a. Mexico.
b. Japan.
c. China. 4. China produces the largest masses of the eight listed resources in the table. 
5. Minerals are naturally occurring solid compounds that have the element while ores must be mined. 
6. Percent of metal in the ore, type of mining and processing used to extract the metal from the ore, and the environmental impact of the mining and metal processing are all factors.
7. It could have more gold in it now.
8. This means the percent of desired mineral being mined.

Blog Question

      I know that the periodic the periodic table is made up of elements that are organized based on their atomic numbers. The number on the top right of the element is called the Atomic Number. The element symbol is the letter(s) in the middle of the element box on the table. The Atomic mass is at the bottom of the element box. The table consists of groups and periods.The color of the  atomic number shows if an element is a  liquid, gas, solid, or unknown. Groups run vertically while Rows, or periods, go from left to right. Elements that have similar properties are in groups. 

Homework #2

#13-25 (p.130)

13. a. row= period b. column= groups
14. sodium (Na) and potassium (K)
15. a. Noble gasses are located in the group all of the way to the right, b. they are monatomic, c. they don't form compounds  
16. a. MgF2 b. GaP2
17. The melting point would be around 70 degrees C
18. I would expect it to be lower.  
19. 

Element Symbol	Number of Protons	Number of Neutrons	Number of Electrons
C	6	6	6
C	6	7	6
Ca	20	21	20
Pt	76	117	78
U	92	146	92

 20. 

a. berylium: 4 protons, 4 neutrons, 4 electrons. 

b. nitrogen: 7 protons, 7 neutrons, 7 electrons. 

c. neon: 10 protons, 10 neutrons, 10 electrons. 

21. A lead atom must have lost two electrons.

22. a. Carbon: 12, Calcium: 41, Platinum: 195, Uranium: 238 b. Carbon has two isotopes 

23. No this is not sufficient because atomic numbers deal with a total rather than specifics on an element.

24. Electrons are much lighter than protons and neutrons.

25. 

Mg-24	24	12	12
Mg-25	25	12	13
Mg-26	26	12	14