Metals. Key Concepts. Name Date Class. Chapter 4 Elements and the Periodic Table Section 3 Summary

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1 Chapter 4 Elements and the Periodic Table Section 3 Summary Metals Key Concepts What are the physical properties of metals? How does the reactivity of metals change across the periodic table? How are synthetic elements produced? Most of the elements are metals. Chemists classify an element as a metal based on physical properties. The physical properties of metals include luster, malleability, ductility, and conductivity. A malleable material can be hammered or rolled into flat sheets and other shapes. A ductile material can be pulled out, or drawn, into a long wire. Thermal conductivity is the ability of an object to transfer heat. Electrical conductivity is the ability to transfer electric current. Many metals are good conductors. Several metals are also magnetic. They are attracted to magnets and can be made into magnets. All metals except mercury are solids at room temperature. The ease and speed with which an element combines with other elements and compounds is called its reactivity. Metals usually react by losing electrons to other atoms. Some metals react with oxygen in the air, forming metal oxides, or rust. This process is called corrosion. The metals in a group, or family, have similar properties. Family properties change gradually as you move across the table. The reactivity of metals tends to decrease as you move from left to right across the periodic table. The metals in Group 1 are the alkali metals. They are so reactive they are never found uncombined in nature. Group 2 of the periodic table contains the alkaline earth metals. While not as reactive as the alkali metals, they are also so reactive that they cannot be found uncombined in nature. The elements in Groups 3 through 12 are called transition metals. They form a bridge between the very reactive metals on the left and the less reactive metals and other elements on the right. Groups 13 through 15 of the periodic table include metals, nonmetals, and metalloids. The metals in these groups are not nearly as reactive as those on the left side of the table. The elements placed below the main part of the periodic table are called the lanthanides and actinides. Lanthanides are mixed with more common metals to make alloys. Many of the actinides are synthetic elements. Scientists make synthetic elements by forcing nuclear particles to crash into one another. Some synthetic elements are made in nuclear reactors. Powerful machines called particle accelerators are used to make synthetic elements with atomic numbers above

2 Metals (pp ) This section describes the properties of metals and the characteristics of the different groups of metals. Use Target Reading Skills Before you read, preview Figure 17 in your textbook. Then, complete the graphic organizer by writing two questions about the figure. As you read, answer your questions. Q. What metals are attracted to magnets? Properties of Metals A. Q. A. Properties of Metals (pp ) 1. Chemists classify an element as a metal, based on its physical and chemical. 2. Circle the letter of the property that is NOT a physical property of metals. a. shininess b. malleability c. brittleness d. conductivity 74

3 Match the term with its definition. Term 3. malleable 4. ductile 5. conductivity 6. reactivity Definition a. The ease with which an element combines with other elements and compounds b. The ability of an object to transfer heat or electricity to another object c. A term used to describe a material that can be pulled out, or drawn, into a long wire d. A term used to describe a material that can be hammered or rolled into flat sheets and other shapes 7. Some metals are ; they are attracted to magnets or can be made into magnets. 8. Is the following sentence true or false? Most metals are solids at room temperature. 9. The slow destruction of a metal through its reaction with oxygen in the air is called. Metals in the Periodic Table (pp ) 10. How does the reactivity of each group of metals change across the table from left to right? 11. Circle the letter of each sentence that is true about alkali metals. a. They are never found as uncombined elements. b. They react with other elements by losing one electron. c. They are often found as pure elements in sea water. d. They are slightly reactive. 12. What are the two most important alkali metals? 75

4 Metals (continued) 13. Circle the letter of each sentence that is true about alkaline earth metals. a. Each is a good conductor of electricity. b. They are never found uncombined in nature. c. They lose two electrons in chemical reactions. d. They are much less reactive than most metals. 14. What are the two most common alkaline earth metals? 15. Circle the letter of each element that is a transition metal. a. gold b. lithium c. copper d. iron 16. Is the following sentence true or false? The transition metals are less reactive than the metals in Groups 1 and Is the following sentence true or false? All of the elements in Groups 13 through 15 are metals. 18. Where are the lanthanides placed on the periodic table? 19. Where are the actinides found on the periodic table? 20. Which element is the heaviest actinide that occurs naturally on Earth? 76

5 21. Complete the concept map about metals. Metals include a. metals d. and actinides b. earth metals Metals in mixed groups c. metals Synthetic Elements (pp ) 22. Uranium has an atomic number of 92. How were all the elements with atomic numbers higher than 92 created? 23. What was the first synthetic element to be made by colliding nuclei in a particle accelerator? 24. Is the following sentence true or false? It is easier to synthesize new elements with very large atomic numbers. 77