Group 4’s Metal and wood presentation
The uses of metal in the past • The first kind of metal that humans used was gold which could be found native at that time. Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC. • Silver, copper, tin and meteoric iron can also be found native, allowing a limited amount of metalworking in early cultures. • Egyptian weapons made from meteoric iron in about 3000 B.C. were highly prized as "Daggers from Heaven". However, by learning to get copper and tin by heating rocks and combining copper and tin to make an alloy called bronze, the technology of metallurgy began about 3500 B.C. with the Bronze Age.
The common properties of metal The common properties of metal are: • They are hard and strong. • They are solids at room temperature (except mercury). • They are shiny when cleaned. • They are good heat conductors. • They have high melting points.
The common properties of wood The common properties of wood are: • They are inflexible. • They float on water. • They are not hard. • They are strong and springy. • They can be cut, shaped, carved and coloured. • They are warm to the touch.
The uses of wood in the past The uses of wood in the past are: • to make buckets, wheels, plough and tools • to burn wood to keep warm, cook their food and to scare away wild animals at night. • To build shelters. • To make small boats like canoes. • To make paper.
Sources: Matthew Cole, 2008, Science Diversity, Singapore Pearson Longman Ho Peck Leng, 2008, I-science Diversity, Singapore EPB Pan Pacific Kate Bedford, 2005, Our World Wood, Great Britain Aladdin Books Ltd.