history+of+metals

The three metallic elements most likely first used by humans were gold, silver, and copper. As the value of these metals increased, so did the demand for them. One of the early cultures most famous for their use of gold were the Ancient Egyptians.




 * Ancient Egypt** (3000 - 4000 B.C.) and the **Bronze Age**[[image:king_tut_mask.jpg width="197" height="273" align="right" caption="Mask of Tutankamen"]]
 * introduced the era of metallurgy (refining and working with metals)
 * were able to smelt (extract from an ore) copper and tin
 * produced the alloy bronze (a homogeneous mixture of copper and tin)




 * The Hittites** (1100 B.C.) and the **Iron Age**
 * the discovery of iron as a much harder metal than copper and bronze was of great importance
 * iron was smelted from its ore to produce tools and weapons
 * the production of steel (harder than iron) as an alloy made from iron and carbon was a technological breakthrough
 * iron and steel were what gave the Hittite Empire the edge on their competition

Iron smelting was a big industry in the 1800's in Pennsylvania. Here is a [|list of known iron furnaces] in the state of Pennsylvania.



The **properties of metals** are now well-known, and here are a few important ones:
 * they have a lustrous (shiny) appearance
 * most are silvery gray in color (Cu and Au are exceptions)
 * they are all solids in normal conditions but Hg, which is a liquid
 * most have densities greater than water (Li, Na, and K are exceptions)
 * they are malleable (can be pounded flat) and ductile (can be rolled into wire)
 * they are good electrical conductors (silver and copper are some of the best)

And to compare, here are some important **properties of the nonmetals**:
 * most have a dull appearance or are transparent gases
 * they vary greatly in color - some are even colorless
 * all three phases of matter are represented - solids, liquids (bromine), and gases
 * most solids are more dense than water; the gases have very low densities compared to water
 * the solids are brittle and crystalline
 * most are poor conductors of electricity (a.k.a. insulators); some are semiconductors; carbon is a good conductor

Finally, the region between the metals and the nonmetals is where elements have properties of both and are called [|metalloids]. For example, silicon is a silvery gray solid, has some conductivity; however, it is a brittle solid and cannot be made into wire. These elements are in contact with the metalloid line, which bisects metals from nonmetals, on the periodic table.

This [|interactive visual periodic table] will provide lots of information and let you see all kinds of samples of each element.

Try this worksheet:

And this online quiz.