francium
/'frænsiəm/
Học thuậtThân thiện
Definition
- Noun:
- A radioactive chemical element: Francium is a highly unstable, naturally occurring radioactive metal. It is classified as an alkali metal in the periodic table.
- A disintegration product: It is produced from the radioactive decay of other elements, notably actinium.
Usage
- Francium is used almost exclusively in scientific research due to its extreme rarity and radioactivity. It has no significant commercial applications.
- In sentences, it is typically used as a subject or object when discussing chemical elements, radioactivity, or the periodic table.
- Example: Francium is the least stable of the naturally occurring elements.
- Example: Scientists study the properties of francium to understand atomic structure better.
Examples
- Noun:
- Francium has the symbol 'Fr' and atomic number 87.
- The half-life of the most stable isotope of francium is only about 22 minutes.
- Traces of francium can be found in uranium minerals.
Advanced Usage
- Scientific Context: The term is primarily used in nuclear physics, chemistry, and materials science.
- Example: Research into francium's atomic spectrum provides tests for fundamental physical theories.
Variants and Related Words
- Francium-223: The most stable isotope of francium.
- Alkali metal: The group of elements (including lithium, sodium, potassium, rubidium, cesium, and francium) to which francium belongs.
Synonyms
- Element 87: A synonym referring to its atomic number.
- Fr: Its chemical symbol.
Notes on Meaning
- Francium is defined solely by its chemical and physical properties as an element. It does not have alternative common meanings or idioms.
- Its key characteristics are its radioactivity, position as the heaviest alkali metal, and its transient nature.
Noun
- a radioactive element of the alkali-metal group discovered as a disintegration product of actinium