actinide
- Noun:
- Any of a series of radioactive elements with atomic numbers 89 through 103: An "actinide" is any chemical element belonging to a specific group in the periodic table. These elements are all radioactive and share similar properties. The series begins with actinium (atomic number 89) and ends with lawrencium (atomic number 103).
- Noun:
- Uranium and plutonium are two well-known actinides used in nuclear reactors.
- The chemist specialized in studying the properties of the actinide series.
- Disposal of radioactive waste containing actinides is a significant challenge.
"Actinide contraction": A phenomenon in chemistry where there is a greater-than-expected decrease in ionic radii across the actinide series, influencing their chemical properties.
- The actinide contraction explains certain periodic trends in the chemistry of these elements.
"Transuranic actinides": Refers specifically to actinide elements with atomic numbers higher than uranium (92), all of which are human-made.
- The transuranic actinides, like americium and curium, are produced in nuclear reactors.
Actinoid (adj/noun): Often used synonymously with "actinide" to describe the series or its elements.
- The actinoid elements are placed in the f-block of the periodic table.
Actinium (noun): The element (atomic number 89) that begins the actinide series.
- Actinoid element: A direct synonym.
- f-block element (from 89 to 103): A broader category specifying the electron orbital block.
Actinide series: The complete set of 15 consecutive chemical elements in the periodic table from actinium to lawrencium.
- The entire actinide series is radioactive.
Minor actinides: In nuclear chemistry, refers to actinides like neptunium, americium, and curium produced in nuclear fuel, which are not the primary uranium or plutonium fuels but are significant for waste management.
- Advanced fuel cycles aim to transmute minor actinides to reduce long-term radioactivity.
- any of a series of radioactive elements with atomic numbers 89 through 103