iridium

/ai'ridiəm/

Thân thiện

A scientist carefully weighs a sample of iridium in the laboratory.

Definition

1. Noun:
   • A heavy brittle metallic element of the platinum group: Iridium is a chemical element (symbol Ir, atomic number 77) known for its high density, hardness, and brittleness. It is a silvery-white metal.
   • Used in alloys: Iridium is primarily utilized in the creation of hard, high-strength alloys that can withstand extreme temperatures and corrosion.
   • Occurs in natural alloys with platinum or osmium: In nature, iridium is most commonly found alloyed with other platinum-group metals, especially in platinum ores and in a natural alloy with osmium known as osmiridium.

Usage

• Iridium is a technical/scientific term used primarily in the fields of chemistry, metallurgy, geology, and certain high-technology industries (e.g., spark plugs, scientific equipment).
• It is a countable noun when referring to the element as a substance (e.g., "a sample of iridium") and an uncountable noun when referring to it as a material.

Examples

• Noun:
  • The pen tip is made from an alloy containing iridium for durability.
  • Scientists study the layer of iridium in the geologic record, which is linked to the asteroid impact that caused the dinosaurs' extinction.
  • This catalyst uses a small amount of iridium.

Advanced Usage

• "Iridium anomaly": In geology and paleontology, this refers to a concentration of iridium in a specific layer of sedimentary rock, most famously the Cretaceous–Paleogene (K–Pg) boundary layer, providing evidence for a massive asteroid impact.
• "Iridium spark plug": A type of high-performance spark plug that uses a fine iridium tip on its center electrode for longevity and efficiency.

Variants and Related Words

• Iridic (adj): Of or containing iridium, especially in a tetravalent state.
  • Iridic compounds are studied in inorganic chemistry.
• Iridiosmium (n): A rare, natural alloy of iridium and osmium; synonymous with osmiridium.

Synonyms

• Element 77: Referring to its atomic number.
• Platinum-group metal (PGM): A categorical synonym, as iridium is one of the six platinum-group metals.

Related Phrases/Compounds

• Iridium satellite constellation: A specific network of communications satellites.
• Iridium dioxide (IrO₂): A chemical compound of iridium used as an anode coating in industrial electrolysis.

Học thuật

Noun

1. a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium

Từ đồng nghĩa

• Ir
• atomic number 77