January 2005 Chemistry Regents #1-10
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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 |
Questions | Answer | Explanations |
| 1 As an electron in an atom moves from the ground state to the excited state, the electron (1) gains energy as it moves to a higher energy level (2) gains energy as it moves to a lower energy level (3) loses energy as it moves to a higher energy level (4) loses energy as it moves to a lower energy level | 1 | excited is a higher energy level than ground |
| 2 Which subatomic particle will be attracted by a positively charged object? (1) proton (3) electron (2) neutron (4) positron | 3 | protons are positive |
| 3 Which conclusion is based on the “gold foil experiment” and the resulting model of the atom? (1) An atom is mainly empty space, and the nucleus has a positive charge. (2) An atom is mainly empty space, and the nucleus has a negative charge. (3) An atom has hardly any empty space, and the nucleus has a positive charge. (4) An atom has hardly any empty space, and the nucleus has a negative charge. | 1 | open space positive nucleus |
| 4 Which two particles have approximately the same mass? (1) proton and neutron (2) proton and electron (3) neutron and electron (4) neutron and positron | 1 | proton and neutron mass =1 amu electron =1/1836 amu |
| 5 Which element has chemical properties that are most similar to the chemical properties of sodium? (1) Mg (3) Se (2) K (4) Cl | 2 | same group on the PT |
| 6 Germanium is classified as a (1) metal (3) nonmetal (2) metalloid (4) noble gas | 2 | on the staircase |
| 7 Which statement correctly describes diamond and graphite, which are different forms of solid carbon? (1) They differ in their molecular structure, only. (2) They differ in their properties, only. (3) They differ in their molecular structure and properties. (4) They do not differ in their molecular structure or properties. | 3 | different structures so different properties |
| 8 What is the chemical formula for copper(II) hydroxide? (1) CuOH (3) Cu2(OH) (2) CuOH2 (4) Cu(OH)2 | 4 | Cu2+ OH- Cu(OH)2 |
| 9 What is the percent composition by mass of aluminum in Al2(SO4)3 (gram-formula mass = 342 grams/mole)? (1) 7.89% (3) 20.8% (2) 15.8% (4) 36.0% | 2 | (part/total ) x 100% ((2 x 27)/342) x100% |
| 10 Which statement describes a chemical property that can be used to distinguish between compound A and compound B? (1) A is a blue solid, and B is a white solid. (2) A has a high melting point, and B has a low melting point. (3) A dissolves in water, and B does not dissolve in water. (4) A does not burn in air, and B does burn in air. | 4 | chemical has to do with reactions |