(chemistry) Any of the 15 radioactive elements of the periodic table from actinium to lawrencium that are positioned under the lanthanides, to which they have similar chemistry.
Used in a Sentence
actinides
Definitions, parts of speech, synonyms, and sentence examples for actinides.
Editorial note
Neutrons at these slower speeds don’t interact with the actinides, so you can’t burn actinides in a traditional uranium reactor.
Examples14
Definitions3
Parts of speech1
Quick take
(chemistry) Any of the 15 radioactive elements of the periodic table from actinium to lawrencium that are positioned under the lanthanides, to which they have similar chemistry.
Meaning at a glance
The clearest senses and uses of actinides gathered in one view.
(chemistry) Any of the 14 elements from actinium to nobelium (lawrencium is excluded by some authors as it is a d-block rather than an f-block element).
(chemistry) (dated) Any of the 14 elements from thorium to lawrencium (actinium having been mistakenly excluded because it was thought to be a d-block element in the past).
Definitions
Core meanings and parts of speech for actinides.
noun
(chemistry) Any of the 15 radioactive elements of the periodic table from actinium to lawrencium that are positioned under the lanthanides, to which they have similar chemistry.
noun
(chemistry) Any of the 14 elements from actinium to nobelium (lawrencium is excluded by some authors as it is a d-block rather than an f-block element).
noun
(chemistry) (dated) Any of the 14 elements from thorium to lawrencium (actinium having been mistakenly excluded because it was thought to be a d-block element in the past).
Example sentences
Neutrons at these slower speeds don’t interact with the actinides, so you can’t burn actinides in a traditional uranium reactor.
The fluoride salts of radioactive actinides and fission products are generally not soluble in water at lower temperatures.
These neutrons easily interact with the actinides, transmuting them into fissile isotopes and then fissioning them to produce energy.
The next step is the reprocessing of spent fuel to separate depleted uranium, plutonium and minor actinides.
A lot of the longer lived actinides cannot be fissioned or transmuted effectively by thermal neutrons so they just build up.
Closed fuel cycles can reduce environmental impacts: chemical separation turns long-lived actinides into reactor fuel.
A great deal of time and money was spent on nuclear reactors that destroy actinides.
If desired, however, the actinides can be further separated offsite with additional post-processing techniques.
The waste in conventional reactors are of two types, fission procucts and higher actinides.
Then there are higher actinides, with halflives up to tens of thousands of years.
They're actinides which are either fissile or can reasonably be converted to fissile isotopes.
There are also actinides with half lives in that range (like, various plutonium isotopes).
Quote examples
Many people like to specifically exclude the actinides (the bottom row which includes uranium & plutonium) from the category "rare earth" because scary!
The actinides can continue to be used as fuel in an appropriate reactor, leaving just small amounts of short-lived (<1000 years), highly-radioactive "ash" as nuclear waste.
Frequently asked questions
Short answers drawn from the clearest meanings and examples for this word.
How do you use actinides in a sentence?
Neutrons at these slower speeds don’t interact with the actinides, so you can’t burn actinides in a traditional uranium reactor.
What does actinides mean?
(chemistry) Any of the 15 radioactive elements of the periodic table from actinium to lawrencium that are positioned under the lanthanides, to which they have similar chemistry.
What part of speech is actinides?
actinides is commonly used as noun.