thulium
Học thuậtThân thiện
Definition
Noun: 1. A chemical element: A soft, silvery-white, malleable metallic element belonging to the lanthanide series (rare earth group) on the periodic table. Its symbol is Tm and its atomic number is 69. 2. A material with specific applications: The isotope thulium-170 emits low-energy X-rays and is used in the production of small, portable X-ray machines for specialized applications.
Usage
Thulium is used primarily in technical and scientific contexts. * It is discussed as a chemical element with specific properties. * It is referenced as a material for specific technological or medical devices.
Examples
- Scientific Context: "Thulium is one of the least abundant rare earth elements."
- Technological Context: "The device utilizes a sealed source of radioactive thulium-170 to generate X-rays."
- Descriptive Context: "Pure thulium has a bright, silvery luster."
Advanced Usage
- In Geology: Thulium is described as occurring in minerals such as monazite, apatite, and xenotime, often alongside other rare earth elements.
- In Research: Due to its unique magnetic and spectral properties, thulium finds use in specialized solid-state lasers and superconductors.
Variants and Related Words
- Thulium-170 (Tm-170): The specific radioactive isotope of thulium used in portable X-ray units.
- Thulia: An old or less common name for thulium(III) oxide (Tm₂O₃).
Synonyms
- Tm (Chemical symbol): The standard abbreviation for the element thulium.
- Rare earth metal / Lanthanide: Category to which thulium belongs. (Note: These are categorical terms, not direct synonyms for the element itself.)
Different Meanings
Thulium does not have common idiomatic meanings or phrasal verbs. Its meaning is strictly confined to its identity as a chemical element.
Noun
- a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime