1. Lesson 18 Metals, non-metals and alloys

2. Learning Objectives List the properties of non-metals (9Ea) define alloys and describe how their properties are useful (9Eb p.60-1) Describe the chemical properties of metal and non- metal oxides with respect to acidity (9Ga)

3. Properties of Non-metals (p56) Low melting and boiling points Poor conductors of heat and electricity Good insulators Not malleable Not ductile Not magnetic Non-metal oxides are acids

4. metal oxides are basic Some are very useful CaO (lime) Glass Cement Steel making Neutralize soil acidity

6. Alloys (p.60) We mix metals to change their properties in order to make them more useful— alloys Copper (soft) + zinc (soft)  Brass (harder) Iron + carbon  cast iron (can be poured) Iron + chromium + nickel  stainless steel (does not rust)

7. Why is an alloy stronger?

8. Activity MetalDensity (g/cm2)Strength (MPa)Relative cost Cast iron7.0-7.4100-2301.5 Mild steel7.8430-4901 Stainless steel7.8460-12008.1 In your notebooks Explain why you think the frames of skyscrapers are built with mild steel Explain why stainless steel would be used for the outside of building Explain why stainless steel is not used for the frames of buildings What would cast iron be used for in building projects

9. Analytical skills New Chemistry Booklet Page 7, acid rain Page 8, periodic table Page 9-10, looking for patterns (graph and answer questions) Page 11-12, which metal reacts better?