Done By: 1)Lee Cheok Feng 2)Benjamin Lim 3)Tan Xue Liang 4)Andre Ng

1. How was metal discovered? Metal was known to ancient man before writing. It was discovered by accident but nobody knows who exactly found it. In the past it was used to make weapons. Now it is use to make a lot of things. For example it is used to make coins and oven.

 Solid at room temperature  Good conductors of heat and electricity  Malleable and ductile  Are usually shiny

Different types of metals Aluminum Copper Gold Iron Nickel Sliver Steel Tin Zinc

Plastic is a common name for Polymers (po-ly-mars) materials made of long strings of carbon and other elements. Each unit in a string is called a monomer (mo-no-mar), and is a chemical usually derived from oil.

The early history of plastic and how was it used for in the past& present The first man-made plastic was invented by Alexander Parkes in 1862,in the USA, he called this plastic Parkesine. Now it is used for water bottles, food containers, pipes, measuring jars and also in CD’s! In the past, it was used for dentures, replacement for ivory, tortoise-shell, and bone, for movie films, ping-pong balls etc

 Anything made from plastics were considered cheap 40 years ago.  The first synthetic plastic was made from the plant material cellulose in  Petroleum is the main source of making today’s plastic. How Plastics Are Made

Characteristics of Plastic  Hard and slippery  Soft and rubbery  Tough and slippery  Flexible  Good insulators of heat or electricity  Light weight  Hygienic  Non-rusting  Easy to shape and colour  Cheap

Resources plastic.html plastic.html plastic.html plastic.html other-materials/when-was-plastic-first-invented other-materials/when-was-plastic-first-invented other-materials/when-was-plastic-first-invented other-materials/when-was-plastic-first-invented airpur/Metals_and_their_uses-WSF43DE7D3-1_En.htm airpur/Metals_and_their_uses-WSF43DE7D3-1_En.htm airpur/Metals_and_their_uses-WSF43DE7D3-1_En.htm airpur/Metals_and_their_uses-WSF43DE7D3-1_En.htm History of Plastics - Plastic Recycling and the Environment History of Plastics - Plastic Recycling and the Environment

Q&A Session! Any Questions?

THE END!!! Thank You for Your Attention!