actinium

/æk'tiniəm/

Thân thiện

A scientist carefully handles a sample of actinium in a laboratory.

Definition

1. Noun:
   • A radioactive chemical element: Actinium is a radioactive metallic element belonging to the actinide series in the periodic table. It is found naturally in trace amounts in uranium ores.

Usage

• Actinium is primarily used in scientific research and as a source of neutrons. It is not used in commercial applications due to its scarcity and high radioactivity.
• The word "actinium" is used as a mass noun when referring to the element as a substance.

Examples

• Noun:
  • Actinium-227 is a radioactive isotope with a half-life of 21.8 years.
  • Scientists study the decay chain of actinium to understand nuclear processes.
  • Uranium ores contain minute quantities of actinium.

Advanced Usage

• "Actinium series": Refers to one of the three classical radioactive decay series, of which actinium-235 is the parent nuclide.
  • The actinium series ends with the stable isotope lead-207.
• In compound terms: While "actinium" itself is the target word, it forms the root for related terms in chemistry.
  • Actinide: The series of elements to which actinium belongs.
  • Actinium compound: A chemical compound containing actinium atoms.

Variants and Related Words

• Actinide (n): Any of the series of 15 metallic chemical elements with atomic numbers from 89 (actinium) to 103 (lawrencium).
• Actinoid (adj/n): Another term for actinide; having properties similar to actinium.

Synonyms

• Element 89: Referring to its atomic number.
• Ac: Its chemical symbol.

Notes on Different Meanings

• "Actinium" has only one primary meaning as the name of the chemical element (symbol Ac, atomic number 89). It does not have idiomatic or phrasal verb uses.

Học thuật

Noun

1. a radioactive element of the actinide series; found in uranium ores

Từ đồng nghĩa

• Ac
• atomic number 89