Chapter 19 Elements and Their Properties Section 1 Metals

Metals Review Located on left side of Periodic Table Ductile, malleable, good conductors of heat & electricity 1-3 valence electrons – tend to lose electrons Form ionic bonds Most solids at room temperature (except) Most reflect light = shiny = luster Metals Review

Metallic Bonding Like a pot luck dinner Metallic bonding is the special type of bonding with positive ions surrounded by a cloud of electrons. Outer level electrons are not held tightly to the nucleus Electrons move freely among the positively charge metallic ions Metallic Bonding

Metallic Bonding Explains Metallic Properties Ductile and malleable – metal doesn’t break because the ions are in layers that slide past each other without losing attraction to the electron cloud Conduct electricity – outer level electrons weakly held and move freely Metallic Bonding Explains Metallic Properties

Alkali Metals Group 1 metals – 1 valence electron Softer than most metals MOST REACTIVE of all metals React violently with oxygen and water Must be stored in unreactive oils Do NOT occur in nature as elements – always in compounds Alkali Metals

Alkaline Earth Metals Group 2 metals – 2 valence electrons Very reactive metals Do NOT occur in nature as elements – always in compounds Alkaline Earth Metals

Groups 3-12 are in transition between groups 1-2 and 13-18 1-3 valence electrons Most familiar metals because they occur as elements in nature Often form colorful compounds Transition Elements

Inner Transition Metals Lanthanides # 58-71 (follow lanthanum) Actinides #90-103 (follow actinium) all radioactive and unstable Transuranium elements elements beyond uranium # 92 all synthetic, all radioactive Inner Transition Metals

Chapter 19 Elements and Their Properties Section 2 Nonmetals

Nonmetals Review Located on right side of Periodic Table (except) NOT ductile, NOT malleable NOT good conductors of electricity and heat 5-7 valence electrons – tend to gain or share electrons. Form ionic or covalent bonds Hydrogen can lose 1 or gain 1 electron Most gases at room temperature NOT shiny Nonmetals Review

Halogens Group 17 7 valence electrons 4 nonmetals, 1 metalloid Fluorine is the MOST chemically active of all elements Halogens

The Noble Gases Group 18 8 valence electrons (except) Chemically stable Exist as isolated atoms No naturally occurring compounds The Noble Gases

Chapter 19 Elements and Their Properties Section 3 Mixed Groups

Metalloids Located in the middle of Periodic Table along the staircase 3-7 valence electrons Can form ionic or covalent bonds Metallic and nonmetallic properties Metalloids

Allotropes are different forms of the same element with different molecular structures. Diamonds – each carbon bonded to 4 other carbons in tetrahedrons. Tight crystalline structures Graphite – each carbon bonded to 3 other carbons in hexagonal layers. 4th electron of each carbon is loosely bonded to the next layer – layers slide past each other – pencils Buckminsterfullerene – buckyball – carbons bonded in soccer ball shape – 1991 used to create nanotubes Allotropes of Carbon

Synthetic Elements Synthetic elements are manmade elements. All have 92+ protons except #43 and #61 Created by smashing existing elements with particles. New elements disintegrate to form other elements Studying how these elements form and how they disintegrate, scientists learn more about the forces holding atoms together. Synthetic Elements