1. A chemical bond results when two nuclei have a simultaneous attraction for A) nucleons B) protons C) neutrons D) electrons 2. What occurs when two fluorine atoms react to produce a fluorine molecule? A) Energy is absorbed as a bond is broken. B) Energy is absorbed as a bond is formed. C) Energy is released as a bond is broken. D) Energy is released as a bond is formed. 3. The elements Li and F combine to form an ionic compound. The electron configurations in this compound are the same as the electron configurations of atoms in Group A) 1 B) 14 C) 17 D) 18 4. Which term indicates how strongly an atom attracts the electrons in a chemical bond? A) alkalinity B) atomic mass C) electronegativity D) activation energy 5. Which element has atoms with the greatest attraction for electrons in a chemical bond? A) beryllium B) fluorine C) lithium D) oxygen 6. Which molecule contains a triple covalent bond? A) H2 B) N2 C) O2 D) Cl2 7. Which pair of atoms is held together by a covalent bond? A) HCl B) LiCl C) NaCl D) KCl 8. Which element reacts with oxygen to form ionic bonds? A) calcium B) hydrogen C) chlorine D) nitrogen 9. A molecular compound is formed when a chemical reaction occurs between atoms of A) chlorine and sodium B) chlorine and yttrium C) oxygen and hydrogen D) oxygen and magnesium 10. Which substance contains bonds that involved the transfer of electrons from one atom to another? A) CO2 B) NH3 C) KBr D) Cl2 11. The chemical bonding in sodium phosphate, Na3PO4, is classified as A) ionic, only B) metallic, only C) both covalent and ionic D) both covalent and metallic 12. Given a formula for oxygen: What is the total number of electrons shared between the atoms represented in this formula? A) 1 B) 2 C) 8 D) 4 13. Which type of substance can conduct electricity in the liquid phase but not in the solid phase? A) ionic compound B) molecular compound C) metallic element D) nonmetallic element 14. Which of the following solids has the highest melting point? A) H2O(s) B) Na2O(s) C) SO2(s) D) CO2(s) 15. What is the total number of electrons shared in the bonds between the two carbon atoms in a the molecule shown below? A) 6 B) 2 C) 3 D) 8 16. Which type of bonding is found in all molecular substances? A) covalent bonding B) hydrogen bonding C) ionic bonding D) metallic bonding 17. A diamond is an example of A) a supercooled liquid B) an ionic compound C) a metallic substance D) a network solid
18. Which statement correctly describes diamond and graphite, which are different forms of solid carbon? A) They differ in their molecular structure,only. B) They differ in their properties, only. C) They differ in their molecular structure and properties. D) They do not differ in their molecular structure or properties. 19. Given the electron dot diagram: The electrons in the bond between hydrogen and fluorine are more strongly attracted to the atom of A) hydrogen, which has the higher electronegativity B) fluorine, which has the higher electronegativity C) hydrogen, which has the lower electronegativity D) fluorine, which has the lower electronegativity 20. Which bond is least polar? A) As Cl B) Bi Cl C) P Cl D) N Cl 21. Which type of bonding is usually exhibited when the electronegativity difference between two atoms is 1.1? A) ionic B) covalent C) metallic D) network 22. The data table below represents the properties determined by the analysis of substances A, B, C, and D. Which substance is an ionic compound? A) A B) B C) C D) D 23. Which terms describe a substance that has a low melting point and poor electrical conductivity? A) covalent and metallic B) covalent and molecular C) ionic and molecular D) ionic and metallic 24. Metallic bonding occurs between atoms of A) sulfur B) copper C) fluorine D) carbon
25. Metallic bonding occurs between metal atoms that have A) filled energy levels and low ionization energies B) filled energy levels and high ionization energies C) unfilled energy levels and low ionization energies D) unfilled energy levels and high ionization energies 26. Which element consists of positive ions immersed in a "sea" of mobile electrons? A) sulfur B) nitrogen C) calcium D) chlorine 27. Which molecule has a nonpolar covalent bond? 28. Which formula represents a molecule having a nonpolar covalent bond? 32. Given the formula representing a molecule: The molecule is H C C H A) symmetrical and polar B) symmetrical and nonpolar C) asymmetrical and polar D) asymmetrical and nonpolar 33. The four single bonds of a carbon atom in CH4 are directed toward the corners of a A) square B) tetrahedron C) rectangle D) parallelogram 34. Which electron-dot structure represents a non-polar molecule? 35. Which electron dot formula represents a polar molecule? 29. Which formula represents a nonpolar molecule containing polar covalent bonds? A) H2O B) CCl4 C) NH3 D) H2 30. Which statement explains why a CO2 molecule is nonpolar? A) Carbon and oxygen are both nonmetals. B) Carbon and oxygen have different electronegativities. C) The molecule has a symmetrical distribution of charge. D) The molecule has an asymmetrical distribution of charge. 31. Which formula represents a polar molecule? A) H2 B) H2O C) CO2 D) CCl4 36. Which of these substances has the strongest intermolecular forces? A) H2O B) H2S C) H2Se D) H2Te 37. At STP, fluorine is a gas and iodine is a solid. This observation can be explained by the fact that fluorine has A) weaker intermolecular forces of attraction than iodine B) stronger intermolecular forces of attraction than iodine C) lower average kinetic energy than iodine D) higher average kinetic energy than iodine
38. The liquids hexane and water are placed in a test tube. The test tube is stoppered, shaken, and placed in a test tube rack. The liquids separate into two distinct layers because hexane and water have different A) formula masses B) molecular polarities C) ph values D) specific heats 39. Given the formula representing a hydrocarbon: The molecular formula and the empirical formula for this hydrocarbon are A) C5H10 and CH2 B) C5H10 and CH3 C) C4H8 and CH2 D) C4H8 and CH3 40. What is the molecular formula of a compound that has a molecular mass of 54 and the empirical formula C2H3? A) C2H3 B) C4H6 C) C6H9 D) C8H12 Base your answers to questions 41 and 42 on the information below. 41. In the space in your answer booklet, draw a Lewis electron-dot diagram for CF4. 42. State evidence that indicates NH3 has stronger intermolecular forces than CF4.
Base your answers to questions 43 and 44 on the information below. Bond energy is the amount of energy required to break a chemical bond. The table below gives a formula and the carbon-nitrogen bond energy for selected nitrogen compounds. 43. Explain, in terms of charge distribution, why a molecule of hydrogen cyanide is polar. 44. State the relationship between the number of electrons in a carbon-nitrogen bond and carbon-nitrogen bond energy. Base your answers to questions 45 through 47 on the table below. 45. Explain, in terms of molecular polarity, why hydrogen chloride is more soluble than hydrogen in water under the same conditions of temperature and pressure. 46. Explain, in terms of intermolecular forces, why hydrogen has a lower boiling point than hydrogen bromide. 47. Explain, in terms of electronegativity difference, why the bond in H Cl is more polar than the bond in H I.
48. Draw the electron-dot (Lewis) structure of calcium chloride. 49. Base your answer to the following question on the information below and on your knowledge of chemistry. A sample of seawater is analyzed. The table below gives the concentration of some ions in the sample. Using the key, draw two water molecules in the box, showing the orientation of each water molecule toward the calcium ion.
50. Determine the percent composition by mass of oxygen in the compound C6H12O6