Name: Total Points /15

Transcription

1 Name: Total Points /15 1. Given: Samples of Na, Ar, As, Rb a. Which two of the given elements have the most similar chemical properties? b. Explain your answer in terms of the Periodic Table of the Elements. 2. Based on the graph below and the Reference Tables, describe the trend in first ionization energy of Group 18 elements as the atomic number increases. castlelearning.com/ /AssignmentPrintin 1/8

2 3. In the 1920s, paint used to inscribe the numbers on watch dials was composed of a luminescent (glow-in-the-dark) mixture. The powdered-paint base was a mixture of radium salts and zinc sulfide. As the paint was mixed, the powdered base became airborne and drifted throughout the workroom causing the contents of the workroom, including the painters' clothes and bodies, to glow in the dark. The paint is luminescent because radiation from the radium salts strikes a scintillator. A scintillator is a material that emits visible light in response to ionizing radiation. In watchdial paint, zinc sulfide acts as the scintillator. Radium present in the radium salts decomposes spontaneously, emitting alpha particles. These particles can cause damage to the body when they enter human tissue. Alpha particles are especially harmful to the blood, liver, lungs, and spleen because they can alter genetic information in the cells. Radium can be deposited in the bones because it substitutes for calcium. Figure 1 Base your answer on the article above, the Reference Tables for Chemistry, and your knowledge of chemistry. Why does radium substitute for calcium in bones? 4. Base your answer to the question on your knowledge of chemical bonding and on the Lewis electron-dot diagrams of H 2 S, CO 2, and F 2 below. Figure 2 Which atom, when bonded as shown, has the same electron configuration as an atom of argon? castlelearning.com/ /AssignmentPrintin 2/8

3 5. Figure 3 Base your answer to the question on the table and grid. State the trend in first ionization energy for the elements in the table as the atomic number increases. castlelearning.com/ /AssignmentPrintin 3/8

4 6. [Refer to figure 3 in question 5] Base your answer to the question on the table. Explain, in terms of atomic structure, why cesium has a lower first ionization energy than rubidium. 7. Explain, in terms of atomic structure, why the atomic radius of iodine is greater than the atomic radius of fluorine. castlelearning.com/ /AssignmentPrintin 4/8

5 8. Base your answer to the question on the data in Reference Table S. Based on the graph below, describe the trend in the boiling points of these elements as the atomic number increases. castlelearning.com/ /AssignmentPrintin 5/8

6 9. Base your answer to the question on the information below. A thiol is very similar to an alcohol, but a thiol has a sulfur atom instead of an oxygen atom in the functional group. One of the compounds in a skunk s spray is 2-butene-1-thiol. The formula of this compound is shown below. Figure 4 Explain, in terms of electron configuration, why oxygen atoms and sulfur atoms form compounds with similar molecular structures. 10. Base your answer to the question on the information below. A metal, M, was obtained from a compound in a rock sample. Experiments have determined that the element is a member of Group 2 on the Periodic Table of the Elements. Figure 5 Explain, in terms of electrons, why element M is a good conductor of electricity. castlelearning.com/ /AssignmentPrintin 6/8

7 11. Base your answer to the question on the information below. The table below lists physical and chemical properties of six elements at standard pressure that correspond to known elements on the Periodic Table. The elements are identified by the code letters, D, E, G, J, L, and Q. Figure 6 Letter Z corresponds to an element on the Periodic Table other than the six listed elements. Elements G, Q, L,and Z are in the same group on the Periodic Table, as shown in the diagram to the left. Based on the trend in the melting points for elements G, Q, and L listed in the Properties of Six Elements at Standard Pressure table, estimate the melting point of element Z, in degrees Celsius. 12. Describe one chemical property of Group 1 metals that results from the atoms of each metal having only one valence electron. 13. Explain, in terms of atomic structure, why the noble gas neon is an unreactive element. castlelearning.com/ /AssignmentPrintin 7/8

8 14. Base your answer to this question on the information below. Two sources of copper are cuprite, which has the IUPAC name copper(i) oxide, and malachite, which has the formula Cu 2 CO 3 (OH) 2. Copper is used in home wiring and electric motors because it has good electrical conductivity. Other uses of copper not related to its electrical conductivity include coins, plumbing, roofing, and cooking pans.aluminum is also used for cooking pans. At room temperature, the electrical conductivity of a copper wire is 1.6 times greater than an aluminum wire with the same length and cross-sectional area. At room temperature, the heat conductivity of copper is 1.8 times greater than the heat conductivity of aluminum. At STP, the density of copper is 3.3 times greater than the density of aluminum. Figure 7 Identify one physical property of aluminum that could make it a better choice than copper for a cooking pan. 15. Base your answer to this question on the information below. Figure 8 Identify one element from this table for each type of element: metal, metalloid, and nonmetal. castlelearning.com/ /AssignmentPrintin 8/8