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  2. Radiocarbon dating - Wikipedia

    en.wikipedia.org/wiki/Radiocarbon_dating

    Radiocarbon dating helped verify the authenticity of the Dead Sea scrolls. Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.

  3. Aldehyde - Wikipedia

    en.wikipedia.org/wiki/Aldehyde

    Aldehyde structure. In organic chemistry, an aldehyde (/ ˈ æ l d ɪ h aɪ d /) is an organic compound containing a functional group with the structure R−CH=O. [1] The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many ...

  4. Calculation of radiocarbon dates - Wikipedia

    en.wikipedia.org/wiki/Calculation_of_radiocarbon...

    The standard used for modern carbon is wood, with a baseline date of 1950. [3] Correcting for fractionation changes the activity measured in the sample to the activity it would have if it were wood of the same age as the sample. The calculation requires the definition of a 13 C fractionation factor, which is defined for any sample material as [4]

  5. Radiometric dating - Wikipedia

    en.wikipedia.org/wiki/Radiometric_dating

    This makes carbon-14 an ideal dating method to date the age of bones or the remains of an organism. The carbon-14 dating limit lies around 58,000 to 62,000 years. [32] The rate of creation of carbon-14 appears to be roughly constant, as cross-checks of carbon-14 dating with other dating methods show it gives consistent results.

  6. Absolute dating - Wikipedia

    en.wikipedia.org/wiki/Absolute_dating

    One of the most widely used and well-known absolute dating techniques is carbon-14 (or radiocarbon) dating, which is used to date organic remains. This is a radiometric technique since it is based on radioactive decay. Cosmic radiation entering Earth's atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide ...

  7. Chronological dating - Wikipedia

    en.wikipedia.org/wiki/Chronological_dating

    Chronological dating, or simply dating, is the process of attributing to an object or event a date in the past, allowing such object or event to be located in a previously established chronology. This usually requires what is commonly known as a "dating method".

  8. Radiocarbon dating considerations - Wikipedia

    en.wikipedia.org/wiki/Radiocarbon_dating...

    C activity if the additional carbon from fossil fuels were distributed throughout the carbon exchange reservoir, but because of the long delay in mixing with the deep ocean, the actual effect is a 3% reduction. [1] [11] A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons and created 14 C.

  9. Homologation reaction - Wikipedia

    en.wikipedia.org/wiki/Homologation_reaction

    Seyferth–Gilbert homologation in which an aldehyde is converted to a terminal alkyne and then hydrolyzed back to an aldehyde. Some reactions increase the chain length by more than one unit. For example, the DeMayo reaction can be considered a two-carbon homologation reaction.