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| Understanding the concepts
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| 1.a.
| An important skill to master is locating various elements in the periodic table. This requires you to know the names and symbols of the elements. Open the Names and Symbols of the Most Common Elements Table on the Web site. With the element column covered, drill yourself on naming the element given the symbol of the element and vice versa.
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| b.
| It's also important is to know the names given to specific groups in the periodic table. Open the Periodic Table on the CD and identify the alkali metals, the alkaline earth metals, the halogens, and the noble gases. Where are the transition metals in the periodic table? Where are the metals? the nonmetals? What are metalloids or semimetals? |
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| 2.a.
| Many early scientists performed experiments to determine the structure of the atom. J.J. Thomson's work with cathode-ray tubes led to the discovery of electrons. Click Visualizations in Chapter 4 on the CD and then choose Cathode Ray Tube to see a video regarding cathode rays and the effect of a magnet on these rays. |
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| b.
| Another scientist who did important work regarding the structure of the atom was Ernest Rutherford. Explain Rutherford's metal foil experiment in terms of the set-up for the experiment, the results of the experiments, and the conclusions taken from the experiment. See Section 4.5 in the text for a discussion of Rutherford's experiment. |
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| 3.a.
| The structure of the atom is a very tiny, very dense nucleus with the electrons moving about the nucleus at relatively large distances. In general, the atom is mostly empty space. What particles make up the nucleus? Which particle in the atom differentiates an atom of oxygen from an atom of nitrogen? What are isotopes? |
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| b.
| What are ions? How do atoms form ions? Do Exercise 4.74 in the text to practice determining numbers of protons and electrons in ions. An important skill to master is predicting the changes for ions that various elements generally form. Which group of elements generally form +1 charged ions? +2 charged ions? -1 charged ions? List some elements that form +3 charged ions (ignore the transition metals) and -2 charged ions. |
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| 4.
| Most elements exist as solids in their elemental form at 25°C. The structures of these solids are complicated. However, some elements exist as diatomic molecules. What are diatomic molecules? What elements exist in nature as diatomic molecules? Open the Elements that Exist as Diatomic Molecules in their Elemental Forms Table on the Web site to check your answers. What nonmetals exist as a collection of individual atoms? |
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| 5.a.
| A main goal in Chapter 4 should be to become proficient at writing formulas for ionic compounds. To practice writing formulas, open the Formation of Ionic Compounds from Ions Understanding Concepts on the CD. Read the introduction and do a few sets of exercises. |
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| 5.b.
| The exercises in the Understanding Concepts gave you the charge of the various ions. However, for some of the elements listed, you should be able to predict the charges on your own (see Activity #3b above). Which elements generally form cations? Which form anions? If an alkali metal reacts with an oxygen to form an ionic compound, what would be the general formula for the compound? What about an alkaline earth metal with a halogen? What about the formula of the compound of aluminum with sulfur? For these questions, first determine the charges of the ions, then you can determine the formula. |
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| 6.
| Check your understanding of key terms in Chapter 4 by opening Key Words on the CD. Come up with your own definition before clicking on the term. |
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| 7.
| Test your understanding of Chapter 4 by taking the ACE quizzes on the Web site. |
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