this ppt includes all details of gold such as history of gold,effect on civilization,extraction of gold and uses.

2. INTRODUCTION
• AMETALisa materialthatistypicallyhard,shiny,hasgood
electricalandthermalconductivity.
• Metalsaregenerallymalleable, fusibleandductile.
• About91ofthe118elementsintheperiodictablearemetals.

3. CONT..
• Goldisoneofthefewelementsthatcanaffectpoliticsand
economics.Warshavebeenfoughtoveraccessto gold.
• Manynations stillcounttheirwealth accordingto theamountof
goldtheykeepinstorage.
• Largeamountsofgoldarestillusedinthemanufactureofcoins,
medals,jewelry,andart.Goldalsohasa numberofusesin
industry,medicine,andotherapplications.Forexample,one
radioactiveisotopeofgoldiscommonlyusedto treatcancer.

4. GOLD
• Symbol :Au
• AtomicNumber :79
• Meltingpoint : 1064.18”c
• Color : yelloworgolden
• Crystalstructure : FCC
• Family: Group11(IB),Transitionmetal

5. HISTORY OF GOLD
• Goldisdiscoveredby JamesW.Marshall.
• Hehaddiscoveredgoldunexpectedlywhileoverseeing constructionofa
sawmillontheAmericanRiver onJanuary24, 1848in california.

6. GOLD CONT..
• TheelementsymbolforgoldisAu.Thesymbolcomesfromtheold
Latinnameforgold, aurum,whichmeans"shiningdawn"or"glow
ofsunrise".
• OneofthespecialskillsdevelopedbytheEgyptianswastheadding
ofgoldto glassobjects.Theyfoundawayto usegoldto makeglass
abeautifulruby-redcolor.Theglassbecameknownasgoldruby
glass.
• Goldisalsomentionedina numberofplacesinthe Bible.

7. FACTS CONT..
• Goldisalsousedinmedicine.TheradioactivegoldisotopeAu-198
candestroytumorcells inthebody.
• IntheUnited states.Thousands ofpeopleflockedto Californiain
searchofgold.ThiserawascalledtheGoldRush.Peoplebecame
veryrich.

8. GOLD IN SPACE ..
• TheJamesWebbSpace Telescopeis thefirst
mostadvanced teliscopeeverbuildby NASA.
• Thehexagons arecoatedwith a thinlayerofgold
becausetheelementisthebestreflectorof
infraredlight,thewavelengththatmarks
extremelyfar-offobjects.
• Anditgiveswonderfulinformationofuniverse.

9. EFFECT ON CIVILIZATION
• Goldhasbeencalledthemostbeautifulofallchemical elements.
• Its beautyhasmadeitdesirableforuseinjewelry,coins,and
artworkforthousandsofyears.
• Itwasoneofthefirstpuremetals to be usedbyhumans.

10. FACTS CONT …
• Thegoldblocksharmfulultravioletraysfromthesun.
• Theworld'slargestgold crystalis thesizeofa golfballandcomes
fromVenezuela.The7.7-ounce(217.78grams)crystalisworth
about$1.5million.
• Earthquakescancreate gold.
• Youcaneatgold…ifyoureallywantto.
Don't fearforyourstomach:Thegoldisn'tdigestedandjustpasses
rightthrough,accordingto EdibleGold,acompanythatsellsgoldleaf.

11. PHYSICAL PROPERTIES
• Goldisbothductileandmalleable.
• Twootherimportantpropertiesareitsreflectivityandlackof
electricalresistance.
• Goldisextremelyductile.28gramsofgoldcanbestretchedintoa
goldthread8kilometerslong . Thesheetwillbeonly0.00025
centimeters(oneten-thousandthofaninch)thick.

12. CHEMICAL PROPERTIES
• Generallyspeaking,goldisnotveryreactive.
• donotcorrode(rust)ortarnishvery easily.
• It don’tdissolvewithacids.
• It cannotcombinewithoxygenandothergases.

13. OCCURRENCE IN NATURE
• Goldoccursinnatureinboth itsfreestate andin compounds
• Themostcommoncompoundsofgoldarethe tellurides.A
tellurideisacompoundoftheelement tellurium resultgold
telluride(AuTe2).

14. • About1/4 oftheworld'sgoldcomesfromSouthAfrica.Otherleading
producersofthemetalaretheUnitedStates,Australia,Canada,
China,andRussia.
• IntheUnitedStates,about 3/4oftheNevada ,California,Montana,
Alaska,and SouthDakotaalsoproducegold.

15. EXTRACTION OF GOLD
• Therearetwowaysto removegoldfrom it’sores.
• OneismixedanorewithMercurymetal. mercurycombineswith
goldintheoreto formanamalgam.
• Goldore+ Mercury  Amalgam.
• Amalgamisa mixtureoftwoaremoremetals.
oneofthemetalisMercury.
• Finallygoldamalgamisremovedfromtheore.
• Goldamalgam  PureGold (heateduptomercurydriveoff).

16. MEASUREMENTS
1karat=1/5ofa gram=200milligrams
KARAT GOLD CONTENT
24 karat 99.95+ %
22 karat 91.6 %
21 karat 87.5 %
20 karat 83.3 %
18 karat 75 %
15 karat 62.5 %
10 katat 41.7 %

17. USES
• Ina 1986study,expertsestimatedthat121,000tonsofgoldhad
beenminedthroughouthistory.
• Ofthatamount,about18,000tonswereused for
industrial,researchandhealth.
• Oftheremaining103,000tonsofgold,abouta third(35,000tons)
hadbeenmade intogoldbarsheldbynationalbanks.
• Finally,theremaining68,000tonsofgoldareownedbyprivate
individuals.Thisgoldexistsintheformofjewelry,coins,or
bullion.Goldbullionarebarsorotherlargepiecesofpuregold.

18. USES CONT..
• Jewelryisthelargestsingleuseofgold.In1996,about3,290tonsof
goldweremadeworldwide.Ofthatamount,nearly85percentwas
madeintojewelry.Thesecondlargestuseofgold(about213 tons)
wasinindustrialdevicesandconsumerproducts.

19. .