Classifying Elements Further

1. Classifying Elements Further • What does each element family have in common? • In general, the elements in a family have the same number of valence electrons.

2. Metals • What are the families of metals? • Families of metals include the alkali metals, the alkaline-earth metals, and the transition metals. • alkali metal:one of the elements of Group 1 of the periodic table • alkaline-earth metal: one of the elements of Group 2 of the periodic table • transition metal: one of the metals that can use the inner shell before using the outer shell to bond

3. Metals, continued • The alkali metals are very reactive. Group 1 • Alkali metals are in Group 1, on the left edge of the periodic table. • They are reactive because they have one valence electron that is easily removed. • They are soft and shiny, and many have similar melting points, boiling points, and densities.

4. Metals, continued • Alkaline-earth metals form compounds that are found in limestone and in the human body. • Alkaline-earth metals are in Group 2. 2 valence electrons • Alkaline-earth metals are less reactive than alkali metals, but still react to form positive ions. • In general, alkaline-earth metals are harder, denser, stronger, and have higher melting points than alkali metals.

5. Metals, continued • Transition metals are in the middle of the periodic table. Groups 3-12 • With the exception of mercury, transition metals are • harder, more dense, and have higher melting points than alkali metals and alkaline-earth metals. • They are also less reactive, but they can form positive ions.

6. Nonmetals • What are some of the families of nonmetals? • Families of nonmetals include the noble gases and the halogens. • noble gas:one of the elements of Group 18 of the periodic table • halogen: one of the elements of Group 17 of the periodic table

7. Nonmetals, continued • The noble gases are relatively inert. 8 valence electrons. • The noble gases are in Group 18. • They exist as single atoms instead of as molecules. • They are inert, or unreactive, because their s and p orbitals are filled. In general, they do not form ions or compounds.

8. Nonmetals, continued • The halogens combine easily with metals to form salts. Group 17. • With the addition of a single electron, halogens become stable. • They combine easily with metals (especially alkali metals) to form salts.

9. Nonmetals, continued • Nonmetals and their compounds are plentiful on Earth. • Six other nonmetals are on the right side of the periodic table. • Carbon can form many compounds. • There are millions of carbon-containing compounds.

10. Semiconductors • What are semiconductors? • As their name suggests, semiconductors are able to conduct heat and electricity under certain conditions.