Lesson Objectives

1. Lesson Objectives • Identify and explain the properties of chemical families in the periodic table • Alkali metals • Alkaline earth metals • Transition metals • Halogens • Noble gases • Chemical Families

2. Periodic table – table that displays the elements in order of increasing atomic number and organizes them according to chemical properties • Elements arranged in a periodic pattern • Behavioral trends of an element can then be predicted by knowing its position on the table • The Periodic Table

3. The Periodic Table

4. Periodic table is arranged in • Periods – rows on the periodic table • Groups – columns on the periodic table • Also called families, since elements in groups share similar chemical properties • Periods and Groups

5. Groups are numbered 1–18 or 1–8 with A/B notation • Tall columns are notated as “A” • Main group elements • Short columns are notated as “B” • Numbering Groups 1A 2A 3B 4B 5B 6B 7B 8B 1B 2B 3A 4A 5A 6A 7A 8A Main Group Elements

6. Family names • Group 1A –– alkali metals • Group 2A –– alkaline earth metals • Group 7A –– halogens • Group 8A –– noble gas • Group 1–8B –– transition metals • Chemical Families 1A 2A 3B 4B 5B 6B 7B 8B 1B 2B 3A 4A 5A 6A 7A 8A

7. Arrangement of elements on periodic table help predict physical and chemical properties including • Physical state • Boiling, melting, or freezing point • Density • Metallic and nonmetallic character • Reactivity • Likelihood of gaining or losing electrons • Valence – number of electrons in the atom’s valence or outermost energy level • Decoding the Periodic Table

8. Step-wise line that begins at the element boron and moves downward in a zigzag pattern divides the table • Metals are to the left of the line • Nonmetals are to the right of the line • Along the line are the metalloids • Possess properties of both metals and nonmetals • Metals, Nonmetals, and Metalloids Metalloids

9. Metals tend to lose electrons to form cations • Cations – positively charged particles • Other properties of metals • Lustrous, good conductors, malleable, and ductile • Nonmetals gain electrons to form anions • Anions – negatively charged particles • Other properties of nonmetals • Many are gases at room temperature, solids are usually brittle, and are typically poor conductors • Metallic and Nonmetallic Character

10. Elements in the same group will have similar chemical properties • Group number of group A elements equals the number of valence electrons • Valence electrons – electrons in the valence or outermost energy level, which are most likely to be lost, gained, or shared • Determines the oxidation number of an element • Positive if electrons are lost • Positive charge equals the number of electrons lost • Negative if electrons are gained • Negative charge is equal in magnitude to the number of electrons gained • Chemical Properties

11. Reactivity is determined by the ability to gain, lose, or share electrons in order to achieve an octet • Octet – eight electrons in the valence energy level • Noble gases naturally have an octet • Extremely low reactivity • Other groups attempt to achieve octets by gaining, losing, or sharing electrons • Higher reactivity • Types of elements involved in the reaction will determine how the octet is achieved • Metals tend to lose electrons when reacting with nonmetals • Nonmetals tend to gain electrons when reacting with metals and share electrons when reacting with other nonmetals • Chemical Properties

12. Noble gases • Gases at room temperature • Relatively inert • Have full valence shells • Typically don’t form ions • Noble Gases 8A 18 By Felix Burton (Flickr) [CC-BY-2.0]

13. Halogens • Highly reactive nonmetals • Seven valence electrons • One electron away from having an octet • Gain one electron to achieve octet • Ions have -1 charge • Very electronegative • Electronegative – possessing the ability to acquire electrons readily • Form ionic bonds by accepting electrons from metals • Form covalent bonds by sharing electrons with other nonmetals • Combine with H+ to form acids • Halogens 7A 17

14. 2A 2 • Alkaline Earth Metals • Alkaline earth metals • Highly reactive metals • Two valence electrons • Two electrons away from having an octet • Loses two electrons to attain octet • Ions have +2 charge • Form oxides by combining with oxygen • Form ionic bonds with nonmetals, creating salts • Combine with OH– to form bases

15. Alkali Metals • Highly reactive metals • One valence electron • One electron away from having an octet • Lose one electron to attain an octet • Ions have +1 charge • Form oxides by combining with oxygen • Form ionic bonds with nonmetals, creating salts • Combine with OH– to form strong bases • Alkali Metals 1A 1

16. Groups 1–8B are collectively called the transition metals • Transition in oxidation numbers • Form different compounds with nonmetals as a result of variance in charges • Less reactive than alkali metals or alkaline earth metals • Transition Metals 3B 4B 5B 6B 7B 8B 1B 2B 3 4 5 6 7 8 9 10 11 12