Presentation Transcript

1. Metals Chapter 19 Section 1

2. Interesting to know • First metal used was gold about 6,000 years ago • Followed a few thousand years later by tin and iron

3. Properties of metal • Metals are found to the left of the stair-step line • Metals usually have common properties such as: • Good conductors of heat and electricity • All but Hg is solid at room temperature • Reflect light (luster) • Malleable –can be hammered or rolled into sheets • Ductile – drawn into wires

4. Properties of metal • Types of bonds formed • Bonds are when elements form with other elements to become new molecules • Often Ionic bonds are formed between metals and nonmetals • Metallic bonding – outer electrons are not held tightly – (this form of bonding explains some properties of metals)

5. Alkali Metals • Group 1 of periodic table • Most reactive of all metals – react rapidly and sometimes violently • Don’t occur in nature in their elemental form • Stored in substances that are unreactive • Has one electrons in its outer electron cloud

6. Radioactive Elements • Definition – element in which the nucleus breaks down and gives off particles and energy • Example would be the last element in group 1 Francium

7. The Alkaline Earth Metals • Group 2 of periodic table • Combine readily with other elements • Two electrons in outer energy level • Some used in fireworks – ex. Magnesium

8. Transition Elements • Transition elements are those elements in group 3 through 12 in the periodic table. • These are considered to be elements in transition between groups 1 and 2 and Groups 13 through 18. • Transition elements are the most common types of typical metals • Often occur in nature as uncombined elements.

9. Iron Triad • Consists of Groups 8,9, and 10 that start with Iron, Cobalt, and nickel • All used in the process to create steel and other metal mixes • Iron – main component of steel – most widely used of all metals • Nickel – added to steel to give strength

10. Coinage Metals • Copper, silver, gold – Group 11 • Stable and malleable • Found as elements in nature • Copper used in wiring because of its superior ability to conduct electricity and its relatively low cost. • Gold and silver are very resistant to corrosion and are attractive in color and thus used in jewelry.

11. Mercury - Hg • Mercury is a silvery, liquid metal – the only metal that is liquid at room temperature. • Used in thermometers, some temperature sensitive switches and some batteries • Poisonous • “Mad as a hatter” -- used mercury in hats

12. Inner Transition Metals • Lanthanides – used very extensively in the motion picture industry and to help produce colors on your tv screen • Actinides – all radioactive and unstable • Uranium is best known for its use in nuclear reactors and in weapons applications

13. Metals in the Crust • Most metals in earth’s crust are found as ores • Ores are metal compounds that have formed a mixture with the rock or clay in the earth.

14. Nonmetals Chapter 19 Section 2

15. Properties of Nonmetals • Usually gases at room temperature or very brittle solids • Not malleable or ductile • Bad conductors • Not shiny • Right side of Staircase line (other than hydrogen)

16. Properties of nonmetals • Type of bonding • Can form ionic or covalent bonds

17. Hydrogen • 90 percent of all atoms in the universe are hydrogen (most found as water) • Formed from Greek word meaning “water forming” • Hydrogen at its elemental form is a gas at room temperature • Hydrogen is found usually as a diatomic molecule (which means it consists of two atoms of the same element in a covalent bond) • H is highly reactive because it only has a single electron that it shares when it combines with other nonmetals. • H can gain an electron when it combines with alkali and alkaline earth metals.

18. The Halogens • Very reactive • Seven electrons in outer energy level and only need one electron to complete this energy level. • If a halogen gains an electron from a metal it will form an ionic compound called a salt. • Some uses: • Chlorine – disinfecting water • Iodine – important in our diet – also used to disinfect skin before surgery

19. Noble gases • Exist as isolated atoms • Stable because their outermost energy levels are full. • Never occur as compounds in nature.