PALLADIUM, SILVER, CADMIUM, INDIUM, TIN, ANTIMONY, TELLURIUM
PALLADIUM
Atomic symbol: Pd
Atomic weight: 106.42
Atomic number: 46
Electron configuration: 2-8-18-18-0
Oxidation states: +2, +4
State of matter: solid
Heavy metal, ductile
Discovered in 1803 by William Hyde Wollaston
Boils at 2927°C, melts at 1552°C
Notes:
Palladium is a silver, white metal that also occurs as a black powder and as spongy masses that can be compressed to a compact mass. It is extremely ductile and often used as a catalyst. Small amounts of palladium alloyed with gold produces the best white gold. Its chief use is for electrical contacts on telephone equipment.
SILVER
Atomic symbol: Ag
Atomic weight: 107.8682
Atomic number: 47
Electron configuration: 2-8-18-18-1
Oxidation states: 1
State of matter: solid
Heavy metal, ductile
Discovered in ancient times
Boils at 2212°C, melts at 960.8°C
Notes:
Silver is a white, precious metal, more malleable and ductile than any other metal except for gold. It is the best conductor of heat and electricity. It is very rare, and the largest percentage of silver is found in lead sulfide. Silver bearing ores are called argentiferous. The biggest demand for silver comes from photography because silver is used in film.
CADMIUM
Atomic symbol: Cd
Atomic weight: 112.411
Atomic number: 48
Electron configuration: 2-8-18-18-2
Oxidation states: +2
State of matter: solid
Heavy metal, low melting
Discovered in 1817 by Freidrich Strohmeyer
Boils at 765°C, melts at 321°C
Notes:
Cadmium is a silvery- white metal that is almost as soft as tin. Like tin, it emits a crackling sound when bent. It is extremely rare, and most cadmium is used in electroplating various alloys to help prevent corrosion.
Atomic symbol: In
Atomic weight: 114.818
Atomic number: 49
Electron configuration: 2-8-18-18-3
Oxidation states: +3
State of matter: solid
Heavy metal, low melting
Discovered in 1863 by Ferdinand Reich and Theodor Richter
Boils at 2080°C, melts at 156.61°C
Notes:
Indium is about as rare as silver. It is a soft, white metal with bluish tinge. Like tin, it emits a screeching sound when bent. It is used in bearing alloys, as a thin film on moving surfaces made from other metals, in dental alloys, and in semiconductor research.
Atomic symbol: Sn
Atomic weight: 118.710
Atomic number: 50
Electron configuration: 2-8-18-18-4
Oxidation states: ++2, +4
State of matter: solid
Heavy metal, low-melting
Discovered in ancient times
Boils at 2260°C, melts at 231.88°C
Notes:
Tin is silver white, lustrous, soft, very malleable, and ductile metal. It Is slightly tenacious, easily powdered, and comes in the form of bars, foil, powder, shot, etc. It is most widely used for solder, metal used for bearings and plating steel cans for food containers. It is nontoxic, and exists in two allotropic forms—white and gray tin. Gray tin changes to white tin when heated to 55.8°F and more rapidly at 212°F. The reverse happens at low temperatures.
Atomic symbol: Sb
Atomic weight: 121.760
Atomic number: 51
Electron configuration: 2- 8 -18-18-5
Oxidation states: ±3, +5
State of matter: solid
Heavy metal: low melting
Discovered in ancient times
Boils at 1380°C, melts at 630.5°C
Notes:
Antimony exists in many allotropic forms, such as a bright silvery white metal, which is hard and brittle. It is a poor conductor of electricity and heat and does not tarnish in air unless the air is moist, in which case it slowly oxides. It shows a rare characteristic of expanding when it solidifies, and thus is good for casting and type metals. Combined with either tin, lead, or copper it forms anti-friction alloys that are used in machinery bearings.
Atomic symbol: Te
Atomic weight: 127.60
Atomic number: 52
Electron configuration: 2-8-18-18-6
Oxidation states: +4, +6, -2
State of matter: solid
Non-metal
Discovered in 1782 by Franz Joseph Müller von Reichenstein
Boils at 989.9°C, melts at 449.8°C
Notes:
Tellurium is a semi-metallic element that physically and chemically resembles selenium. Tellurium exists in two forms: a silvery-white brittle, crystalline solid that has a metallic luster, and an amorphous powder that is dark gray to brown. It burns in air and oxygen with a blue- green flame.
