SNC 1D1 – Metals metals usually have the following properties: Usually shiny.

1. SNC 1D1 – Metals metals usually have the following properties: Usually shiny. Good conductors of electricity. Solids at room temperature (except for mercury). malleable (can be hammered into a shape). Ductile (can be pulled into a long thin wire). Most react with acids. Example: gold (Au), silver (Ag), potassium (K)

2. Metal Mixtures • Most metal objects are mixtures of metallic elements. • Stainless steel is a mixture of iron, nickel and chromium. • A metal produced by blending different metal elements together is an alloy. • other example include brass (Cu and Zn) and bronze (Cu and Sn).

3. Uses of Metals • Gold and silver are used to make fine jewellery but pure gold is too soft instead it must be alloyed with copper and silver to harden it. • The karat rating of gold is an indication of how pure the gold is 24 karat gold is purest while 10 karat gold is the least pure. • Gold and aluminum are easily hammered and rolled into foil. • Copper is used in wiring because it is an excellent conductor, it does not corrode easily and it is relatively inexpensive.

4. Dangerous Metals • Nickel is often used to make posts and wires for jewellery worn in piercings. Many people are allergic to nickel and can develop a rash. • “Heavy metals” such as mercury and lead are very dense and were once used in mining and industry. When foods with mercury or lead are eaten they can damage internal organs such as the brain, liver and kidneys. • Lead is commonly mixed with other metals to provide strength and durability. Lead crystal can be up to 24% lead. Lead can react with acids like those in fruit juice or wine and cause the metal to come out of solution.

5. Lead crystal

6. Plumbing in many older buildings is held together with solder that contains lead. Both copper and solder are toxic and can be removed from pipe with hot water. Homework Page 223 # 1 - 4

7. Soldering copper pipe