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August 2002 Chemistry Regents #21-30
Highlight to reveal answers and explanations
Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 |
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Questions | Answer | Explanations |
| 21 The spontaneous decay of an atom is called (1) ionization (3) combustion (2) crystallization (4) transmutation | 4 | definition of transmutation |
| 22 In any redox reaction, the substance that undergoes reduction will (1) lose electrons and have a decrease in oxidation number (2) lose electrons and have an increase in oxidation number (3) gain electrons and have a decrease in oxidation number (4) gain electrons and have an increase in oxidation number | 3 | reduction charge goes down, gain electrons (GER) |
| 23 Which electron configuration is correct for a sodium ion? (1) 27 (3) 281 (2) 28 (4) 282 | 2 | ION- lose an electron 2-8 |
| 24 In which equation does the term "heat" represent heat of fusion? (1) NaCl(s) + heat -->NaCl(l) (2) NaOH(aq) + HCl(aq) -->NaCl(aq) + H2O(l) + heat (3) H2O(l) + heat --> H2O(g) (4) H2O(l) + HCl(g) -->H3O+(aq) + Cl-(aq) + heat | 1 | fusion is melting, solid to liquid |
| 25 Which substance is an Arrhenius acid? (1) LiF(aq) (3) Mg(OH)2(aq) (2) HBr(aq) (4) CH3CHO | 2 | acids start with H+ |
| 26 Which type of emission has the highest penetrating power? (1) alpha (3) positron (2) beta (4) gamma | 4 | gamma most penetrating then beta then alpha |
| 27 As the elements in Group 17 are considered in order of increasing atomic number, the chemical reactivity of each successive element (1) decreases (2) increases (3) remains the same | 1 | nonmetals fluorine is most reactive (top right) |
| 28 As the pressure on the surface of a liquid decreases, the temperature at which the liquid will boil (1) decreases (2) increases (3) remains the same | 1 | less pressure lower BP, table H |
| 29 As a Ca atom undergoes oxidation to Ca2+, the number of neutrons in its nucleus (1) decreases (2) increases (3) remains the same | 3 | lose electrons not neutrons |
| 30 As the temperature of a liquid increases, its vapor pressure (1) decreases (2) increases (3) remains the same | 2 | Table H |
Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50
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