Metals

1. Metals Coach Medford Building Science Champions

2. Objectives • Describe chemical and physical properties of metals • Identify and describe different kinds of metals, and compare the properties of the various families of metals

3. Key Terms • Malleable • Ductile • Conductor • Magnetic • Alloy • Corrosion • Alkali metals • Alkaline earth metals • Transition metals • Lanthanide • Actinide

4. Elements • The majority of elements are metals • 92 are found in nature, most are metals • Each classification of elements have their own unique characteristics

5. Metals • How can you tell if something is metal? • Hard • Shiny • Magnetic • Malleable • Ductile • Conductors of electricity

6. Physical Properties of Metals • Chemists classify an element as a metal based on physical properties such as hardness, shininess, malleability and ductility • Malleable – can be pounded into shapes • Ductile – able to be pulled into wires • Conductors – transmit heat and electricity • Magnetic – attraction between 2 or more metals • Corrosion – Wearing away of soft metals, oxidation

7. Physical Properties of Metals • Good conductors of heat and electricity • Some are magnetic • SOLID at room temperature • Very high melting point ~ 3,400 degrees C • Mercury is the exception; it is a liquid at room temperature

8. Chemical Properties of Metal • Wide range of chemical properties • Some metals are very reactive • Sodium reacts violently with water • Gold is nonreactive and does not lose its shine in air • Most metals fall between sodium and gold

9. Alloys • A mixture of metals is called an alloy • The metals do not mix chemically so therefore they do not lose their individual properties • Examples: • Steel • Brass • Bronze

10. Metals in the Periodic Table • The metals in a group, or family, have similar properties and these family properties change gradually as you move across the table • Metals are less reactive as you move from left to right • Metals on the periodic table are located to the left of the metalloids

11. Alkali Metals • Group 1 on the Period table from lithium to francium • They are always found as compounds in nature • Why do you think they are always found as compounds in nature? • They have 1 valence electron. • Very soft, reactive & stable with other elements • 1 valence electron • Easily combine with halogens (group 17)

12. Alkaline Earth Metals • Group 2 on the periodic table • Not as reactive as group 1. • Most common are magnesium and calcium • 2 valence electrons • Easily lose valence electrons Magnesium – MG Atomic # = 12 Atomic Mass = 24.305

13. Transition Metals • Form a bridge between very reactive metals and less reactive metals • Very similar to one another • Include most familiar metals: Gold, copper, silver, nickel and iron • Good conductors of electricity • Fairly stable, slow to react with water and air Groups 3-12

14. Metals in Mixed Groups • Groups 13 – 16 • To the right of the transition metals • Common elements: aluminum, tin and lead

15. Rare Earth Metals Lanthanides Actinides Bottom row of the bottom, separated section of the periodic table Only thorium and uranium are found in nature The rest are created in labs Very unstable • Top row of bottom, separated section of the periodic table. • Soft, malleable, shiny with high ductility • Used for various alloys • Found in nature • Have similar properties to one another

16. Review • Metals have many physical properties • Family one is the alkali metals • Family 18 is the noble gases • Transition metals form a bridge between the left and right side of the periodic table

17. References • Anderson, M. et all (2012) Physical Science. McGraw-Hill: Columbus • Frank, D.V et al (2001). Physical Science. Prentice Hall: New Jersey