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เอกสารมาตรฐาน
สหรัฐอเมริกา
APHA
SMWW 3500-Ir
Iridium
2023
1
Standard methods for the examination of water and wastewater (543.3 APHA 24th ed. Ref. Treatises&monographs FL2)
Iridium (Ir) is the eighth element in Group VIII of the periodic table. It has an atomic number of 77, an atomic weight of 192.2, and valences of 1, 3, and 4. The average abundance of Ir in the earth’s crust is probably <0.001 ppm, and in groundwaters it is <0.1 mg/L. Iridium occurs uncombined with platinum and other metals. It is used in alloys with platinum in catalysts, thermocouples, electrodes, and wires...