SILVER (Ag)
Silver is white lustrous metal. It is an excellent conductor of heat and electricity. It is also highly ductile and malleable metal. Its polished surfaces are good reflectors of light. Formation of thin layer of oxide or sulphide on its surface makes it relatively unreactive.
It is widely used in society. It is used in Jewellery, decorative items and silver tableware because it does not tarnish and maintain its silvery shiny appearance.
It is used to make mirror because it is best reflector of visible light.
Silver forms compounds of significant importance. Silver Nitrate (\ce{AgNO3}) or Lunar caustic is used in detection of Halogen.
Light sensitive material \ce{AgBr} and \ce{AgI} are used in Photographic films.
GOLD (Au)
Gold is a soft yellow metal. It is most malleable and ductile of all the metals. One gram of gold can be drawn into a wire of one and a half kilometre long. Gold is very non-reactive or inert metal. It is not affected by atmosphere. It is not even affected by any single mineral acid or base.
Gold has importance in our society. It is used in Jewelry because it has very high lustre, yellow colour, and tarnish resistance.
Gold is used in electronic components because it is highly efficient conductor of current and cannot corrode.
Gold is used in connecting wires, connection strips, switches, and relay contacts to make electronic devices highly reliable.
Therefore, Gold is used in cell phones, global positioning systems, Calculators etc.
Gold is used in Laptop Computers for rapid and accurate transmission of digital information.
It is used in dentistry because it is chemically inert, non-allergic and easy for dentist to work.
Gold coated polyester films are used in space vehicles to reflect infrared radiation and stabilize the temperature of space vehicle.
The helmet of Astronaut is coated with thin film of gold which reflect intense Solar radiation and protect eyes, skin of astronauts.
Glass surface coated with gold will reflect solar radiations outward and keep the buildings cool in summer.
It also reflects internal heat inward and keeps the building warm in winter. Gold symbolizes purity, beauty, and stability so it is used in making medals, trophies award etc.
PLATINUM (Pt):
It is a silvery white corrosion resistance metal. It is paramagnetic transition metal. It is used in chemical reactions as catalyst.
Platinum is used to make jewelry items because of its unique characteristics like colour, beauty, strength, flexibility, and resistance to tarnish. It provides a secure setting for diamonds and other gemstones, enhancing their brilliance.
An alloy of platinum, palladium and rhodium is used as catalyst in automobiles as catalytic converter. It converts most of the toxic gases (CO, NO2) being emitted by vehicles into less harmful carbon dioxide, nitrogen and water vapour.
Platinum is used in the production of hard disk drive coatings and fiber optic cables.
Platinum is used in the manufacturing of fiber glass reinforced plastic and glass for liquid crystal displays (LCD).
Its density is more than Gold. So, it is more expensive than Gold.
