1. 1 The mass of a proton is approximately equal to the mass of (1) an alpha particle (3) a positron (2) a beta particle (4) a neutron   1   2   3   4   Hint Half-n-half Clue   2. 2 An orbital of an atom is defined as the most probable location of (1) an electron (3) a positron (2) a neutron (4) a proton   1   2   3   4   Half-n-half Clue   3. 3 What must occur when an electron in an atom returns from a higher energy state to a lower energy state? (1) A specific amount of energy is released. (2) A random amount of energy is released. (3) The atom undergoes transmutation. (4) The atom spontaneously decays.   1   2   3   4   Half-n-half Clue   4. 4 Which element is a liquid at 305 K and 1.0 atmosphere? (1) magnesium (3) gallium (2) fluorine (4) iodine   1   2   3   4   Half-n-half Clue   5. 5 Which list of elements consists of a metal, a metalloid, and a nonmetal? (1) Li, Na, Rb (3) Sn, Si, C (2) Cr, Mo, W (4) O, S, Te   1   2   3   4   Half-n-half Clue   6. 6 At STP, which physical property of aluminum always remains the same from sample to sample? (1) mass (3) length (2) density (4) volume   1   2   3   4   Half-n-half Clue   7. 7 Which statement describes a chemical property of silicon? (1) Silicon has a blue-gray color. (2) Silicon is a brittle solid at 20.°C. (3) Silicon melts at 1414°C. (4) Silicon reacts with fluorine.   1   2   3   4   Half-n-half Clue   8. 8 Which diagram represents a mixture of two different molecular forms of the same element?   1   2   3   4   Half-n-half Clue   9. 9 A compound is broken down by chemical means during (1) chromatography (3) electrolysis (2) distillation (4) filtration   1   2   3   4   Half-n-half Clue   10. 10 Which quantities must be conserved in all chemical reactions? (1) mass, charge, density (2) mass, charge, energy (3) charge, volume, density (4) charge, volume, energy   1   2   3   4   Half-n-half Clue   11. 11 Which phrase describes the distribution of charge and the polarity of a CH4 molecule? (1) symmetrical and polar (2) symmetrical and nonpolar (3) asymmetrical and polar (4) asymmetrical and nonpolar   1   2   3   4   Half-n-half Clue   12. 12 What is the charge of the nucleus of an oxygen atom? (1) 0 (3) +8 (2) -2 (4) +16   1   2   3   4   Half-n-half Clue   13. 13 Which ion has no electrons? (1) H+ (3) Na+ (2) Li+ (4) Rb+   1   2   3   4   Half-n-half Clue   14. 14 To break a chemical bond, energy must be (1) absorbed (3) produced (2) destroyed (4) released   1   2   3   4   Half-n-half Clue   15. 15 Which Lewis electron-dot diagram represents a nitrogen atom in the ground state?   1   2   3   4   Half-n-half Clue   16. 16 What is the most likely electronegativity value for a metallic element? (1) 1.3 (3) 3.4 (2) 2.7 (4) 4.0   1   2   3   4   Half-n-half Clue   17. 17 Which polyatomic ion has a charge of 3-? (1) chromate ion (3) phosphate ion (2) oxalate ion (4) thiocyanate ion   1   2   3   4   Half-n-half Clue   18. 18 Every chlorine atom has (1) 7 electrons (2) 17 neutrons (3) a mass number of 35 (4) an atomic number of 17   1   2   3   4   Half-n-half Clue   19. 19 Which substance can not be broken down by a chemical change? (1) ammonia (3) propane (2) methanol (4) phosphorus   1   2   3   4   Half-n-half Clue   20. 20 At standard pressure, which substance becomes less soluble in water as temperature increases from 10.°C to 80.°C? (1) HCl (3) NaCl (2) KCl (4) NH4Cl   1   2   3   4   Half-n-half Clue   21. 21 Which type of concentration is calculated when the grams of solute is divided by the grams of the solution, and the result is multiplied by 1 000 000? (1) molarity (3) percent by mass (2) parts per million (4) percent by volume   1   2   3   4   Half-n-half Clue   22. 22 Which type of energy is associated with the random motion of atoms and molecules in a sample of air? (1) chemical energy (3) nuclear energy (2) electrical energy (4) thermal energy   1   2   3   4   Half-n-half Clue   23. 23 The temperature of a sample of matter is a measure of the (1) total kinetic energy of the particles in the sample (2) total potential energy of the particles in the sample (3) average potential energy of the particles in the sample (4) average kinetic energy of the particles in the sample   1   2   3   4   Half-n-half Clue   24. 24 Which unit is used to express the pressure of a gas? (1) mole (3) kelvin (2) joule (4) pascal   1   2   3   4   Half-n-half Clue   25. 25 Which sample of matter sublimes at room temperature and standard pressure? (1) Br2(ℓ) (3) CO2(s) (2) Cl2(g) (4) SO2(aq)   1   2   3   4   Half-n-half Clue   26. 26 Given the diagram representing a closed system at constant temperature: Which statement describes this system at equilibrium? (1) The mass of H2O(ℓ) equals the mass of H2O(g). (2) The volume of H2O(ℓ) equals the volume of H2O(g). (3) The number of moles of H2O(ℓ) equals the number of moles of H2O(g). (4) The rate of evaporation of H2O(ℓ) equals the rate of condensation of H2O(g).   1   2   3   4   Half-n-half Clue   27. 27 Which reaction occurs at the cathode in an electrochemical cell? (1) combustion (3) oxidation (2) neutralization (4) reduction   1   2   3   4   Half-n-half Clue   28. 28 Which substance yields H+(aq) as the only positive ion in an aqueous solution? (1) CH3CHO (3) CH3COOH (2) CH3CH2OH (4) CH3OCH3   1   2   3   4   Half-n-half Clue   29. 29 Compared to the mass and the penetrating power of an alpha particle, a beta particle has (1) less mass and greater penetrating power (2) less mass and less penetrating power (3) more mass and greater penetrating power (4) more mass and less penetrating power   1   2   3   4   Half-n-half Clue   30. 30 During a nuclear reaction, mass is converted into (1) charge (3) isomers (2) energy (4) volume   1   2   3   4   Half-n-half Clue