final study guide

·      Stronger attractions among atoms result in high boiling point

·      A CuO sample should weight more since the oxygen combines with the Cu and now gets weighed

·      Burning hydrocarbons such as methane releases CO2 gas and water vapor and heat energy

·      If one mole of potassium metal has a mass of 31.9 grams, 6.02 x 10²² atoms are in 3.91 grams potassium

·      Metals conducting electricity is a physical property

·      Diamond is the strongest allotrope of carbon

·      We made two types of alloy in the Alloy lab

·      The alloy in the metal brass has a different hardness than that of copper

·      In the carbon cycle, carbon is not found in the molecules of H20

·      Burning natural gas, coal, and gasoline releases CO2, which threatens the ozone layer

·      Radio waves have the lowest frequency and least energy

·      The best description of water and acetone in a distillation apparatus is:

o   The acetone boils then re-condenses into a beaker, then the water boils separately and re-condenses into a beaker

·      Destroying rainforests leads to more CO2 in the atmosphere

·      Driving cars with internal combustion gasoline engines leads to more CO2 in the atmosphere

·      Plant photosynthesis takes away CO2 from the atmosphere

·      The burning of fossil fuels release CO2 and decrease O2 in the atmosphere

·      7 electrons are in the outer shell of F    

·      OIL RIG- oxidation is lost, reduction is gained

·      Renewable source- can be replenished by natural processes

·      Nonrenewable source- cannot be replenished by natural processes

·      Doping- adding impurities to a semiconductor to enhance its electrical conductivity       

·      Cathode- an electrode in an electrochemical cell at which reduction occurs

·      Anode- an electrode in an electrochemical cell at which oxidation occurs

·      Hydrocarbons- molecules composed of only carbon and hydrogen atoms

·      The fewer carbon atoms there are, the lower the boiling point is        

·      If it ends in “gen” ,“u“ or ”ine” it is a diatomic element  (GEN-U-INE)

day 3 week 6

3 SAS: 

31. a. propane C3H8 

       b. pentane C6H12

32. "-ane" refers to the carbon bonds. 

33. Yes, the molecules are all isomers of each other because they have the same molecular formulas but different arrangement of atoms. 

34. on paper 

35. The shortest-chain alkane that can demonstrate isomerism is butane. 

36. An unbranched hydrocarbon molecule can be represented as a linear chain as well as a zig-zag chain as long as it is composed of four or more atoms. 

37. on paper 

38. a. long straight chain 

        b. a long branched chain 

        c. a short branched chain 

3 SBS: 

1. Petroleum is sometimes considered "buried sunshine" because petroleum's plant energy is found from the sun and is now buried under the ground. 

2. a. potential energy is stored energy, and an example is a spring within a toy 

     b. kinetic energy is energy related to motion, and an example is a toy moving, triggering the spring to unwind

3. In a chemical reaction, a chemical bond is broken and reactant atoms reorganize to form new bonds. 

4. A molecule of methane has more potential energy because the overall chemical change is exothermic. 

5. a. potential energy 

    b. potential energy 

    c. kinetic energy 

    d. potential energy 

    e. kinetic energy 

6. Energy is required to break chemical bonds because there is no other way to break the bonds and order reactant atoms to reorganize and from new bonds. 

7. a. exothermic 

     b. exothermic

     c. endothermic 

8. The quantity of energy stored in the bonds of the reactants compared with the quantity of energy stored in the bonds of the products is greater, thus creating an exothermic reaction. 

9. on paper

10. The law of conservation of energy states that energy can change form but cannot be created or destroyed in any chemical reaction or physical change. 

day 2 week 6

B.3 


1. Human exposure to ultraviolet radiation is potentially more harmful than exposure to infrared radiation because certain forms of radiation can lead to skin cancer and sunburn. 


2. Visible solar radiation plays a major role in the interaction of visible light with electrons in chlorophyll molecules, (photosynthesis), and it also causes red sunsets and blue skies because of the scattering of the sun's radiation. 


3. Dry, arid regions in the US experience wider air temperature fluctuations from night to day than do states with more humid conditions because as warmer air expands, it's density decreases and the warmer air is then displaced by colder, denser air, causing the warmer air to rise. Another factor could be the earth's rotation which influences wind patterns. 


4. a. The warmer the air is, the density decreases and is then replaced by colder air. 
     b. The colder the air is, the density increases and is replaced by warmer air. 


B.8 


1. 100 kg of carbon dioxide is produced daily by all 10 Riverwood High School buses. 


2. 40 liters of fuel are consumed daily by buses idling at Riverwood High School. 


3. In a 180-day school year, 18,000 kg of carbon dioxide would be released into the atmosphere by these buses while idling. 7,200 liters of duel would be consumed. 


Unit 3 SAS


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


3. Petroleum is used as a fuel and is converted to gasoline. Petroleum is also used as a raw material from which many products are manufactured. 


5. Crude oil is called "crude" because it is not processed or refined in its natural state, therefore we can not commercially use it until it is transported. 


6. a. 23,843
    b. 21,220


7. Propane and gasoline are fuels obtained from crude petroleum. 


8. Clothing, CDs, sports equipment, and roller skates are items made from petroleum 
  
10. a. The Middle East has the most petroleum reserves relative to its population 
       b. Western Europe has the least petroleum reserves relative to its population 


11. a. North America and Western Europe consume a greater proportion of petroleum than they possess 
      b. The Middle East and Africa consume a smaller proportion of petroleum than they posses 


12. Separation of two different liquids will only work if the substances are insoluble in each other. 


13. Acetone and water would be easiest to separate from each other by distillation because they are insoluble. 


15. on paper 


16. Fractional distillation does not separate each compound in crude oil, and it produces several distinctive mixtures instead. 


17. Light- refined oils 
       Intermediate- gas oil
       Heavy- wax 


18. The fraction with the highest boiling point range will be at the bottom of the distillation tower. 


19. The fractional distillation process could be repeated until the components of each fraction are fully separated. 


20. Pentane, hexane, octane, and methane. 


21. A covalent bond is a bond formed by the sharing of electrons between atoms. 


22. Atoms with filled outer electron shells do not form covalent bonds because they can be bonded separately. 


23. The analogy describes the sharing of electrons both working together to hold the same atoms together in a covalent bond. 


26. a. a structural formula illustrates the complete concept of a molecule in a graphical representation, whereas the molecular formula is a less detailed representation of a molecule. 
        b. a structural formula is an inadequate representation of an actual molecule because there is not an accurate representation of where an electron's mass is located. 


27. on paper 


28. The electron-dot representation of a carbon atom shows only four dots because it only represents the valence electrons for carbon. 


29. on paper 


30. a. 108 
        b. 192 
        c. 120 
        d. 216

day 1 week 6

Unit 4 BS: 


1. The frequency of electromagnetic radiation is directly proportional to its energy. 


2. The word "spectrum" is a good descriptor of the types of energy found in electromagnetic radiation because it represents the particular types of electromagnetic radiation with each type representing a range of energy.


3. Visible light is useful in plant photosynthesis while other forms are not because visible light interacts with electrons in chlorophyll molecules, which provides the energy needed for photosynthesis. 


4. a. infrared, visible light, ultraviolet   
     b. infrared radiation is heat radiation, visible light is the only light that is visible to the human eye, ultraviolet radiation is necessary for human exposure because vitamin D is produced when the skin receives moderate doses included in sunlight


5. Ultraviolet light is effective for sterilizing protective goggles, while visible light is not, because UV-C radiation is the most energetic form and kills bacteria and destroys viruses. 


6. Infrared radiation from the sun cannot reach Earth's surface because it is absorbed by CO2 and gaseous H20 molecules in the atmosphere. Visible radiation, particularly the scattering of the sun's radiation by water, air, and dust is the cause of red sunsets and blue skies. If all the Ultraviolet radiation reaching the atmosphere actually reached the surface of the earth, the earth would be destroyed. But UV radiation exposure is necessary because of the vitamin D produced. 


7. Two main effects of the solar radiation that reaches Earth's surface are the warming of the atmosphere, oceans, and continents. Another effect is the production of the hydrologic cycle.


8. a. Lake water reflects light and absorbs heat when exposed to sunlight. Asphalt quickly warms up when exposed to sunlight. 
     b. Water in the form of vapor is a greenhouse gas and it absorbs infrared light, and asphalt reflects light directly. 


Unit 4 SBS: 


14. Atmospheric CO2 and water vapor help maintain moderate temperatures at Earth's surface by helping form carbohydrates through photosynthesis. 


15. a. natural process- photosynthesis
            human process- clearing forests
       b. natural process- methaneogenesis 
            human process- fossil fuel production 


16. a. increase- if sufficient CO2 were added, the atmosphere could retain enough additional infrared radiation from the sun to increase Earth's surface temperature. 
       b. decrease- reduce greenhouse emissions by developing energy efficient technologies and relying more heavily on renewable energy. 


17. A greenhouse with transparent glass walls is warmer than a structure with opaque wooden walls because the greenhouse effect causes the trapping and returning of infrared radiation. 


18. on paper 
CO2 gas, CaC03, CH4


19. CO2 gas, CaC03, and CH4 are chemical reservoirs of carbon atoms.


20. Over time, a particular carbon atom can be part of the atmosphere as a gas, the lithosphere as animal or plant waste, and the hydrosphere as limestone.

day 5 week 5

2SDS: 


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


8. White gold and stainless steel are examples of common alloys. 


9. Fe (iron) is a component of both steel and stainless steel. 


10. Ni3Al is a low-density, strong metallic alloy of nickel and aluminum and it is used as a component of jet aircraft engines. 


11. The location of semiconductors and metalloids are the same on the periodic table. 


12. Three elements that are commonly used for doping semiconductors are phosphorus, arsenic, aluminum, and gallium. 


13. The primary use of the products of semiconductor technology is silicon-based items. 

day 4 week 5

2SCS: 


18. a. Reusing is using an item again after it has been initially used. Recycling is processing reused materials into new products. 
      b. Reusing grocery bags, recycling water bottles 


19. a. water, oxygen, timber, sun 
       b. copper, oil, gas, coal


20. a. reusing 
        b. recycling 
        c. reusing


21. The life cycle of a light bulb and a newspaper are similar because in both processes, raw materials are obtained and then refined into the desired material. 


2SDS: 


1. An allotrope is a different form of an element that has distinctly different physical or chemical properties. 


2. Oxygen and nitrogen form allotropes. 


3. a. The properties of a diamond, a chunk of coal, and pencil lead are different because: a diamond has the highest melting point among all of the other elements and it's cost depends on it's quality and esthetic characteristics, a chunk of coal is not very expensive, and pencil lead is made of graphite. 
     b. Their properties are different because the atoms are bonded together differently
     c. The cut, appearance, and quality of these materials all effect and differentiate their costs


4. Engineered materials differ from natural materials because they are made for specific purposes and can be made up of natural materials, however, natural materials are untouched and unaltered through manmade changes.  


5. Two advantages of using engineered ceramics in high-temperature applications are that the efficiency is increased, therefore fuel use is reduced. A disadvantage is that ceramics can fracture if exposed to sudden temperature changes. 


6. Polyethylene can be tailored to display properties for specific applications. Optical fibers are also being developed to replace conventional copper. 

extra credit report #5

Why we sunburn 

• Researchers have discovered a molecular signal that triggers sunburns

• When our skin cells are exposed to UVB radiation, a specific form of RNA is damaged. The damaged RNA is then released as a signal of solar injury and triggers the healthy cells to create the production of factors that induce inflammation

• The point of the entire process is to remove the sun-damaged cells, because they  could turn cancerous if not cleared away 

• People with certain auto immune disorders are very sensitive to sun exposure, and blocking the RNA pathway could be a way to reduce inflammation in these patients. However, blocking the RNA in healthy patients just to reduce the risk of sunburn could be dangerous because this process is an important way for the body to heal and get rid of damaged cells 

• "The inflammatory response is a normal part of our protection against the sun", said Dr. Gallo, a professor of medicine at the University of San Diego 

http://www.scientificamerican.com/article.cfm?id=why-we-sunburn