Can a Playground be too Safe?

Changes in playgrounds have been made to increase safety, but is it really beneficial for American children? Parents, and manufacturers, are concerned about the safety of children at the playground, and many new additions have been made to enforce this. These changes include shorter slides, enclosed platforms, and rubber or woodchip replacements for the pavements. Although it seems like fewer injuries are occurring, the children could be becoming damaged physiologically. The playground used to be a place to learn and encounter and conquer fears, but without those exciting heights, those fears may come back during later life. Even though children may fail and injure themselves, the fear is over because the worse case scenario has already happened. Also, studies have been proven to show that children, who fall and injure themselves at an early age, have a lesser chance of developing a fear of heights in their later teenage years. According to Dr. Sandester, children use the same progressive techniques developed by therapists to help adults confront their phobias. Adults fear small injuries, and take precautions to prevent their kids from getting hurt. However, not being exposed to these harmless injuries can cause children to be more fearful. Manufacturers as well are concerned about playground safety, but because of a fear of lawsuits. However, the safety precautions made are capable of causing more wounds. For example, the new soft surfaces increased the risk of long fractures in the arm, as noted by Dr. David Ball (a professor and Middlesex University in London). Another damaging change is the reduced height of playground equipment. Although this addition is beneficial for toddlers, it has a different affect for children the age of 10. Without the exciting heights, older children are not motivated to partake in healthy exercise outside, or may resort to exploring dangerous places. More changes in playground equipment in New York include removal of seesaws, merry-go-rounds, tire swings, and ropes that led from one platform to another. Although these familiar structures have been removed, they are being replaced by more creative gear like climbing walls with artificial rocks. Whatever fears adults may have, the dangerous situations are overshadowed by the accomplishment of conquering fears and developing a sense of mastery.

“It’s fun,” she said. “I’d like to see it in our playground. Why not? It’s kind of dangerous, I know, but if you just think about danger you’re never going to get ahead in life.”- Nayelis Serrano, 10-year-old from the South Bronx

Article: Can a Playground be too Safe?  

Unit 3: Section B Summary: 1-10

1.    Petroleum is called “buried sunshine” because the energy it contains originated from the sun.

2.    Types of Energy:

a.    Potential energy is energy that is stored up and ready for use; it is also referred to energy of position. Example: a car at the top of a hill.

b.    Kinetic energy is energy associated with the motion of an object. Example: a bouncing ball.

3.    During a chemical reaction, bonds are either destroyed or formed.

4.    Butane has more potential energy because it has more atoms, therefore more energy to give off.

5.     Kinetic or potential:    

a.    Potential

b.    Potential

c.    Kinetic

d.    Potential

e.    Kinetic

6.    Energy is required because it takes force to pull apart the bonds, or to remove the electrons.

7.    Endothermic or Exothermic:

a.    Exothermic

b.    Endothermic

c.    Exothermic

8.    There is more energy in the gases and heat given off, then the energy needed to break the bonds within the candlewick.

9.    On paper

10. Energy is neither created nor destroyed in any mechanical, physical, or chemical process. 

Unit 3: Section A Summary: 1-38

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

2.    Skip

3.    Petroleum is combustible, so it can be used for burning for fuel and its raw state can be created into an array of useful products.

4.    Skip

5.    Crude oil means it still contains impurities, and must be refined for use.

6.    U.S. Petroleum Use:

a.    3 million

b.    16 million

7.    From crude petroleum we get natural gas, kerosene, diesel, petrochemicals, and refined oils.

8.    Petroleum products:

a.    Clothing, carpeting, CDs, and sports equipment.

b.    I don’t know.

9.    Skip

10. World Petroleum use:

a.    Eastern Europe

b.    Central Asia, Far East, and Oceania

11. World Petroleum Consumption:

a.    Everywhere except Central and South America, Africa, and the Middle East.

b.    Central and South America, Africa, and the Middle East.

12. If the liquids were insoluble in one another.

13. Acetone and water because they have very different boiling points.

14. Skip

15. On paper

16. Unlike regular distillation, fractional distillation is a continuous process and produces several distinct mixtures.

17. Light: kerosene, refined oils, and motor gasoline; Intermediate: gas oil, diesel fuel oil, and heavy furnace oil; Heavy: petroleum jelly, lubricating oil and grease, and road asphalt.

18. In a fractional distillation tower the highest temperature would be at the bottom because crude oil is heated up first and when it reaches the tower it cools off as it rises.

19. Filtering or doing a simpler distillation method.

20. Hexane, methane, octane, and pentane. The stronger the intermolecular forces, the higher the boiling point is.

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

22. Atoms with filled outer shells do not need to form covalent bonds because they contain all the electrons necessary, making them un-reactive.

23. The two dogs oppose each other, but are attracted because of the sock, which is like the way atoms bond through electrons.

24. Skip

25. Skip

26. Structural formulas:

a.    A structural formula tells us what shape a molecular formula is in.

b.    It is inadequate because it does not represent the electrons correctly.

27. On paper

28. Because only the valence electrons are represented.

29. Molecular formulas:

a.    C9H20

b.    C16H34

c.    C10H22

d.    C18H38

30. Molar mass:

a.    128 g

b.    226 g

c.    142 g

d.    254 g

31.

a.    Propane, C3H8

b.    Pentane, C5H12

32. It implies that it is an alkane molecule.

33. Yes they are, because they contain the same atoms but are just formed in different structures.

34. On paper

35. ?

36. They are both correct because more than 3 carboned hydrocarbons can create many different structures.

37.

a.    On paper

b.    The branched molecule has a lower boiling point because it bonds are as strong.

38.

a.    A long chain, because the short chain would have tighter bonds.

b.    A long branched chain, because the shorter one will have stronger intermolecular bonds.

c.    A short branched chain, because straight chains have stickier bonds.

Final Blog Topic: What I got out of Summer Chem

For me, it was really important learning about the seriousness of water shortages and pollution on Earth. I live in a house where water is constantly available for me, even for silly things like filling up a water gun. I was aware of how poorer countries did not always recieve enough water, but I never fully realized how serious their conditions were. They have to walk miles to reach a water source, and even then the water is most likely not pure and contain harmful substances. Although people are providing clean water to them, they are charging them money they don't even have. Learning about this, and documenting how much water my household uses daily makes me feel selfish. I use water to wash my dog, that is purer than the water they drink. Summer chem helped me discover all of this, and more, and I will always remember the concepts that apply to my everyday life.

Unit 4: Section B Summary: 14-20

                  

14. CO2 and water vapor in the atmosphere help maintain the earth’s surface temperature in a few ways.  During the day, when the sun’s rays beam down, the gas molecules block and adsorb a majority of the radiation, preventing the temperature on Earth from reaching high levels. During the night, the heat adsorbed by the gases in the morning is released; keeping the temperature up and not letting it get too cold.

15. Natural processes and human activity:

a.    Natural: the carbon cycle. Human: burning waste.

b.    Natural: cow matter. Human: raising livestock and refining fossil fuels.

16. Composition of atmosphere:

a.    A lower concentration of greenhouse gases would cause the earth’s temperature to increase.

b.    An increase of gas molecules would decrease the temperature of Earth because fewer radiation rays would reach the surface.

17.  A greenhouse would be warmer than a structure with opaque wooden walls because the radiation waves that enter the greenhouse cannot escape, but the ones inside the wooden walls can.

18. Greenhouse effect:

a.     A greenhouse: 

  

b.    The global greenhouse:

19. Chemical reservoirs of carbon include carbon dioxide, limestone, solid calcium carbonate, and methane.

20. Carbon atoms follow the carbon cycle, which takes them through all parts of the Earth. When carbon is released as carbon dioxide it enter the atmosphere. After being received by plants for respiration, it is now in the form of glucose and enters the hydrosphere in that form, or as carbon dioxide. The oxygen that is released by plants is inhaled by humans and exhaled as carbon dioxide (making it a part of the biosphere). It is eventually inhaled by underwater plants, or formed into limestone, which eventually decays and returns to the lithosphere. 

B.3: 1-4, page 344

1.    Ultraviolet is more harmful than infrared radiation because it has energy and power. Its most energetic form can destroy bacteria and viruses, meaning that it can cause damage to human skin.

2.    When visible radiation is beamed through the atmosphere, it is scattered causing the blue sky and red sunsets. Another use of visible light is the energy it provides for photosynthesis. This is essential because from photosynthesis we obtain oxygen, which is necessary for human life.

3.    The dryer states have a higher fluctuation in weather because of their concentration of greenhouse gases. The more humid states obviously have more water vapor, which holds in the heat from the day. The more arid states do not contain high amounts of gas molecules meaning that the beams of radiation are not blocked as well during the day, and the heat is not kept in at night.

4.     

a.    If Earth had fewer gas molecules, the daytime would be hotter because there would be enough molecules to adsorb the radiation coming from the sun, therefore increasing the temperature.

b.    On the other hand, fewer gas molecules would cause nights to be cooler. This is because there would not be enough gas molecules to hold in the heat to maintain a steady temperature during the night.

Unit 4: Section B Summary: 1-8

1.    The higher the frequency of electromagnetic radiation, the more energy it contains.

2.    The word “spectrum is a good descriptor because it is defined as a broad sequence of related quantities.

3.    Visible light assists photosynthesis because it can energize electrons in some chemical bonds. Infrared radiation does not contain enough energy, and ultraviolet is too harmful.

4.    Electromagnetic Radiation:

a.    Infrared radiation, visible light, and ultraviolet radiation.

b.    Infrared is basically heat energy and affects the temperatures of nonliving and living things, including Earth. Visible radiation powers plant photosynthesis, which releases oxygen into the atmosphere. Ultraviolet, in its one of its most energetic states, is linked to skin cancer, but the vitamin-D it provides is necessary for human health.

5.    Visible radiation does not provide enough energy to be able to sterilize lab goggles. Ultraviolet light, on the other hand, has photon with enough energy to break covalent bonds (in its UV-C form) therefore killing and destroying bacteria and viruses.

6.    Infrared radiation is mostly absorbed by carbon dioxide and water vapor in the atmosphere and does not reach the Earth’s surface, however, some its higher energy waves are absorbed by the earth and re-radiated as infrared energy. 90% of the visible radiation emitted from the sun reaches the earth and is scattered by water, air, and dust, casing the red sunsets and blue skies. Ultraviolet radiation in general does not reach the earth’s surface. UV-C is completely absorbed by the stratosphere, and most UV-B and UV-A radiation is absorbed by the ozone layer as well.

7.    Solar radiation that reaches Earth’s surface increases its temperature after being trapped by greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Another affect is the increase of water vapor. The more radiation, the hotter it gets causing more water to evaporate and enter the atmosphere.

8.    Heat capacity:

a.    A lake will heat up more easily than asphalt because it can store more heat.

b.    The cause of this is because water has a high specific heat capacity than asphalt and other land materials. 

Unit 2: Section D Summary: 7-13

                  

7.    An alloy is a solid solution consisting of atoms of two or more metals. They can be created through heat and modify the properties of metals.

8.    One alloy that is used commonly is brass. This is an alloy of copper and zinc and is used in plumbing, lighting fixtures, rivets, screws, and ships. Another common alloy is pewter. Pewter is a mixture of tin, copper, bismuth, and antimony and is used for figurines and other decorative objects.

9.    Carbon is a nonmetal that is a component of both steel and stainless steel.

10. An example of a well-defined compound is Ni3Al, a nickel and aluminum metallic alloy. It has a low density, but is very strong and is used in jet aircraft engines.

11. Semi-conductors, since they are not completely non-conductive, but not entirely strong conductors, are placed in between metals and nonmetals. This is because metals are good conductors and nonmetals are not, so putting the semiconductors in between is logical.

12. Some elements commonly used for doping semiconductors are boron, arsenic, and phosphorous.

13. Semiconductors are used for electronic devices like transistors and integrated circuits for computers. They also allow computers to process digital information. 

Unit 2: Section D Summary: 1-6

1.    An allotrope is a different form of an element that has distinctly different physical properties, but has to be in the same state as the original element (for example solid iron and molten iron have different properties but are not allotropes since one is a liquid).

2.    Oxygen and aluminum both form allotropes.

3.    Diamond, coal, and pencil lead:

a.     Diamond is a hard substance, does not conduct electricity, and is colorless. Coal is powdery and used for fuel. Graphite is black, slippery, electrically conductive, and soft.

b.    Their properties vary because of their structures.  Diamond has tightly knit bonds, while graphite’s bonds are looser, making it an ideal lubricant.

c.    The appearance, quality, usefulness, and quantity account for their costs.

4.    Engineered materials sometimes have different properties than their original substances to make them more durable and useful for a job.

5.     Ceramics can operate at high temperatures, rather than metals, and have very high melting points. However, ceramics are very brittle and can crack during rapid changes in temperature. For example, when an engine starts cooling down the ceramic will crack and could lead to engine failures.

6.    To make plastics more useful, increasing their resistance to heat would be useful. For example, accidentally placing a plastic plate on a hot surface will cause it to melt resulting in a sticky mess. Increasing their melting points would help avoid these inconveniences. Also, finding a new way to make plastics would decrease pollution and waste caused by plastic materials. Inventing a decomposable substance that is renewable would greatly please the public.

Unit 2: Section C Summary: 18-21

                                                                       (non renewable)

18. Reusing and recycling:

a.    Reusing is using items that can be refurbished or repaired, rather than sent to a landfill. Recycling is gathering certain items to be reprocessed, allowing them to be used again.

b.    Reusing: reusable water bottles and donating clothes to charity. Recycling: cardboard and tires can be recycled.

19. Renewable and nonrenewable resources:

a.    Renewable: trees, animal waste, fruits, and wind.

b.    Nonrenewable: nuclear power, minerals (copper, gold, silver), helium, and lignite (soft, brown fuel).

20. Recycling or reusing:

a.    Reusing

b.    Recycling

c.    Reusing

21. A light bulb is produced from plastics, chemicals and glass, while a newspaper contains plants and some chemicals. A newspaper can be thrown away in a trashcan, but light bulbs must be disposed of carefully taking into consideration the chemicals contained inside. The problem is the mercury, which incandescent light bulbs do not contain. When recycling, newspapers can just be shredded up and put into the cycle again, but light bulbs must be carefully taken apart.

Unit 2: Section C Summary: 13-17

                 

13.  3 PbO(s) + 2 NH3(g) à 3 Pb(s) + N2(g) + 3 H2O(l)

a.    6 moles NH3

b.    5 mol N2

c.    5 mol Pb

14. 3 PbO(s) + 2 NH3(g) à 3 Pb(s) + N2(g) + 3 H2O(l)

a.    1 mol N2

b.    621 g Pb

c.    28 g N2

d.    447 g PbO

15. ?

16. Percent by mass:

a.    93% Ag

b.    53% Al

c.    40% Ca

17. A 50.0-g sample of ore contains 5.00 g lead (II) sulfatee, PbSO4:

a.    68% Pb in lead sulfate

b.    9% lead (II) sulfate in ore

c.    6% lead in the ore.

d.    On paper

Section C Summary: 1-12

1.    The law of conservation of matter states that in a chemical reaction matter is neither created nor destroyed.

2.    A scientific law summarizes what has been learned by careful observation of nature.

3.    The expressions “using up” and “throwing away” are misleading because matter is never destroyed. Instead, matter is changed into new substances chemically, like a gas.

4.    Atom inventories:

a. Reactant side: Sn=1, H=1, F=1

   Product side: Sn=1, H=2, F=2

   This is an unbalanced equation.

b. Reactant side: Si=1, O=2, C=1

   Product side: Si=1, C=2, O=1

  This is an unbalanced equation.

c. Reactant side: Al=1, O=3, H=6, Cl=3

  Product side: Al=1, O=3, H=6, Cl=3

  This is a balanced equation

5.    Coefficients:

a.    3

b.    2

c.    1

6.    On paper

7.    Balancing equations:

a.    1 Ca3(PO4)2 + 3 H2SO4 à 2 H3PO4 + 3 CaSO4

b.    2 C8H18 + 25 O2 à 16 CO2 + 18 H2O

8.    More balancing:

a.    Reactant: Na=2, S=1, O=4, K=2, Cl=1; Product: Na=2, S=1, O=4, K=2, Cl=1

b.    No they did not, because they added subscripts to the equations, which does not create a correctly balanced equation.

c.    Na2SO4 + 2 KCl à 2 NaCl + K2SO4

9.     

10. Molar Nass:

a.    32 g

b.    48 g

c.    100 g

d.    58 g

e.    224 g

11.They each equal 1.00 mol of substance because their atoms don’t weigh the same or take up the same amount of density. One mol is going to be different for each substance.

12.