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Vulcanization is the process whereby the polymer chains of natural rubber are cr

ID: 510880 • Letter: V

Question

Vulcanization is the process whereby the polymer chains of natural rubber are cross-linked by the addition of which element? a. carbon b. sulfur c. oxygen d. nitrogen In general, the best way to dispose of plastics is a. composting b. incineration c. in landfills d. recycling An apple hanging on a branch above Isaac Newton's head has a. force energy b. kinetic energy c. potential energy d. rotational energy The largest portion of Earth's incident solar radiation a. power the water cycle b. is converted to heat c. power photosynthesis d. is reflected back to space When solid NaOH is dissolved in water, the water gets hotter, indicating that this dissolving is an a. endothermic process because it absorbs heat b. endothermic process because it releases heat c. exothermic process because it absorbs heat d. exothermic process because it releases heat In the process represented by the equation H_2O(l) rightarrow H_2O(g), the entropy a. decreases b. depends on the catalyst c. increases d. remains the same The octane rating for gasoline is a measure of the fuel's a. concentration of octane (C_8H_18) b. energy content in kilocalories c. power rating d. tendency to cause knocking Fission, not fusion, is used in nuclear power plants because fusion a. uses expensive transuranium elements as fuel b. produces less heat than fission c. produces waste products that are radioactive for centuries d. requires temperatures of millions of degrees, making the reaction difficult to contain Which of the following is an n-type semiconductor? a. arsenic doped with silicon b. arsenic doped with germanium c. silicon doped with arsenic d. silicon doped with boron The fuel used by almost all current fuel cells is a. electricity b. hydrogen c. natural gas c. propane The energy that comes from the internal heat of the Earth is a. bioenergy b. geothermal energy c. hydroelectricity d. solar energy

Explanation / Answer

13. Sulfur

14. Recycling

15. Potential energy

16. is reflected back in space

17.exothermic process because it releases heat

18. Increases

19. tendency to cause knocking

20. requries temperature of million degrees, making the reaction difficult to contain

21. Silicon doped in arsenic

22. hydrogen

23. geothermal energy