radiocarbon
part of speech
noun (radiocarbon, uncountable); adjective (radiocarbon)
meaning for a pupil
1) (science) A kind of carbon, called carbon-14, that is slightly radioactive and slowly breaks down over thousands of years. tree →
2) (adjective) Using carbon-14 to find out how old something is: «radiocarbon dating». tree →
sense in the lessons
In science and history lessons radiocarbon dating tells how old once-living things are (wood, bone, cloth), up to about 50,000 years. All living things take in carbon-14; after they die it slowly disappears, so scientists measure what is left. Phrases: «radiocarbon dating», «radiocarbon age», «radiocarbon test».
examples
- Radiocarbon dating showed the wooden boat was 3,000 years old. tree →
- Scientists used radiocarbon to date the bones in the cave. tree →
- Radiocarbon dating only works on things that were once alive. tree →
- The Shroud of Turin was tested by radiocarbon dating in 1988. tree →
- You cannot use radiocarbon to date dinosaur bones; they are far too old. tree →
- Half of the radiocarbon in a sample breaks down in about 5,730 years. tree →
note
Uncountable. Also called carbon-14 or C-14. Maths: its half-life is about 5,730 years, so after 5,730 years half is left, after 11,460 years a quarter is left. Myth: radiocarbon dates dinosaurs — false; dinosaurs are tens of millions of years old, so other methods are used on rocks.
Trees and pragmatics
Every meaning and example of «radiocarbon» parsed by Mova, each sentence with its dependency tree and frames.