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Transcript of Gold
Megan Bates, Tiffany Chen, Emmy Jacobs-Schwartz
5/5/10 Au ~Atomic number: 79
~Atomic mass: 196.9665
~Element Group: Transition Metals (Group 11)
-Gold objects dating to 2600 BC have been found
-This precious metal was discovered in royal tombs in the ancient civilization of Ur, which proves that humans had already learned to work with gold even this early in history
-Gold is also mentioned in many passages in the Bible (For example it is mentioned in the book of Exodus and refers to clothing worn by Aaron)
-Writings found from many stages of human history tell of the discovery of gold. For example, the Romans found it lying in stream beds in the Tagus river in Spain. It was also discovered in Italy, Greece, Turkey, India, and America.
-Christopher Columbus found gold nuggets lying on the bottom of rivers and harbors in Haiti.
-In the United States, the most famous place to find gold is here in California. Thousands of people came here in search of this metal. This time in history is known as the California gold Rush.
-melting point of 1,064.76C (1,948.57F)
-boiling point of 2,700C (4,900F)
Physical properties Cont’d:
-Density of 19.3g/cm3
-lack of electrical resistance
- doesn’t react with oxygen (it will never rust),
chlorine, or bromine
•Gold can be used in many different ways:
Money has to be identifiable, lasting, stable and have a consisted value. Gold is known to be the only material in the world that meets all of there standards
Gold is very ductile and malleable, which makes it very easy to shape and form into different things.
Ever since gold was first discovered, its main function has been ornamental
Still today, gold’s main use is for jewelry making.
Gold doesn’t react to air and most other substances. It is a good conductor of heat and electricity.
These properties of gold make it a great material for electrical switching mechanisms and plug contacts.
One radioactive isotope of gold is used widely in medicine
It has two major uses:
•It can be made into a form called colloidal gold which, when injected can detect whether or not someone’s liver is functioning properly
•In some forms of cancer that are around the stomach and intestines, it can kill the cancer cells
Throughout many different cultures, gold has been identified with the gods, power, and wealth.
Everyone has associated gold with someone or something divine or powerful at least once in their life.
•Less than 50% of all the gold in the world is still in the ground.
•The largest gold nugget ever found weighed 195 pounds .
•The term "gold" comes from an old Anglo-Saxon world “gelo”, which means yellow.
•Gold is able to conduct electricity and heat.
•The chemical symbol for gold is Au from the Latin word “aurum”, which means "shining dawn".
•copper and gold were the first metal to be discovered by man
•native Scottish gold is the purest, at 22.8 carats
•Gold is one of the first pure metals to be used by humans
•Gold is one of the few elements that can affect politics and economics
•1 lb of gold actually weighs less than a pound of feathers because gold is measure differently- it is measured with the troy system and 1 lb of gold is really only 12oz.
a pound of feather weighs 4 more ounces than a pound of gold
•It can be injected into a plant or animal without causing harmful effects
The End These gold bricks can also be used as currency. This is an original poster from the California gold rush. This is King Tutankhamun's tomb, his sarcophagus was plated with gold. In the Olympics, the gold medals are made with pure gold. In most situations, when gold is used for currency, it is in the form of gold coins. This is Mesogold, a brand of colloidal gold that can be injected into the body to test liver functioning abilities. This is a gold ring.