January 2010 Chemistry Regents #76-78

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Questions

Base your answers to questions 76 through 78 on the information below.

Carbon has three naturally occurring isotopes, C-12, C-13, and C-14. Diamond and graphite are familiar forms of solid carbon. Diamond is one of the hardest substances known, while graphite is a very soft substance. Diamond has a rigid network of bonded atoms. Graphite has atoms bonded in thin layers that are held together by weak forces. Recent experiments have produced new forms of solid carbon called fullerenes. One fullerene, C60, is a spherical, cagelike molecule of carbon.

76 Determine both the total number of protons and the total number of neutrons in an atom of the naturally occurring carbon isotope with the largest mass number. [1]

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6 protons and 8 neutrons

Carbon-14 has 6 protons (atomic number) and 8 neutrons (14-6=8)

77 Identify the type of bonding in a fullerene molecule. [1]

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covalent

78 State, in terms of the arrangement of atoms, the difference in hardness between diamond and graphite. [1]

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Diamond has atoms bonded strongly in a three dimensional network. Graphite has atoms that are held weakly between layers.

On to Questions 79-81

 

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

Questions 51-52 Questions 53-55 Questions 56-57 Questions 58-60 Questions 61-63 Questions 64-65 Questions 66-68 Questions 69-71 Questions 72-75 Questions 76-78 Questions 79-81  Questions 82-84

 
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