What type of radioactive decay is involved in carbon dating

Gamma rays, which are unaffected by the electric field, must be uncharged. Because the loss of an α particle gives a daughter nuclide with a mass number four units smaller and an atomic number two units smaller than those of the parent nuclide, the daughter nuclide has a larger n:p ratio than the parent nuclide.If the parent nuclide undergoing α decay lies below the band of stability (refer to Chapter 21.1 Nuclear Structure and Stability), the daughter nuclide will lie closer to the band.

In most cases, the energy emitted will be in the form of an X-ray.

Like positron emission, electron capture occurs for “proton-rich” nuclei that lie below the band of stability.

The beta particle (electron) emitted is from the atomic nucleus and is not one of the electrons surrounding the nucleus. Emission of an electron does not change the mass number of the nuclide but does increase the number of its protons and decrease the number of its neutrons.

Consequently, the n:p ratio is decreased, and the daughter nuclide lies closer to the band of stability than did the parent nuclide.

The loss of an inner shell electron leaves a vacancy that will be filled by one of the outer electrons.

As the outer electron drops into the vacancy, it will emit energy.

We classify different types of radioactive decay by the radiation produced. Alpha particles, which are attracted to the negative plate and deflected by a relatively small amount, must be positively charged and relatively massive.

Beta particles, which are attracted to the positive plate and deflected a relatively large amount, must be negatively charged and relatively light.

Ernest Rutherford’s experiments involving the interaction of radiation with a magnetic or electric field (Figure 2) helped him determine that one type of radiation consisted of positively charged and relatively massive α particles; a second type was made up of negatively charged and much less massive β particles; and a third was uncharged electromagnetic waves, γ rays.

We now know that α particles are high-energy helium nuclei, β particles are high-energy electrons, and γ radiation compose high-energy electromagnetic radiation.

Whether electron capture or positron emission occurs is difficult to predict.

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