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  2. Alpha particle - Wikipedia

    en.wikipedia.org/wiki/Alpha_particle

    Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. [5] They are generally produced in the process of alpha decay but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.

  3. Naturally occurring radioactive material - Wikipedia

    en.wikipedia.org/wiki/Naturally_occurring...

    Radium radionuclides emit alpha and beta particles as well as gamma rays. The radiation emitted from a radium 226 atom is 96% alpha particles and 4% gamma rays. The alpha particle is not the most dangerous particle associated with NORM, as an external hazard. Alpha particles are identical with helium-4 nuclei.

  4. Rutherford scattering experiments - Wikipedia

    en.wikipedia.org/wiki/Rutherford_scattering...

    For Rutherford's alpha particle scattering from gold, with mass of 197, the reduced mass is very close to the mass of the alpha particle: = + = For lighter aluminium, with mass 27, the effect is greater: = + = a 13% difference in mass. Rutherford notes this difference and suggests experiments be performed with lighter atoms.

  5. List of alpha emitting materials - Wikipedia

    en.wikipedia.org/wiki/List_of_alpha_emitting...

    List of alpha emitting materials. The following are among the principal radioactive materials known to emit alpha particles. 209 Bi, 211 Bi, 212 Bi, 213 Bi. 210 Po, 211 Po, 212 Po, 214 Po, 215 Po, 216 Po, 218 Po. 215 At, 217 At, 218 At. 218 Rn, 219 Rn, 220 Rn, 222 Rn, 226 Rn.

  6. Bragg peak - Wikipedia

    en.wikipedia.org/wiki/Bragg_peak

    The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter. For protons, α-rays, and other ion rays, the peak occurs immediately before the particles come to rest. It is named after William Henry Bragg, who discovered it in 1903 using alpha particles from radium, [1 ...

  7. Alpha decay - Wikipedia

    en.wikipedia.org/wiki/Alpha_decay

    v. t. e. Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or "decays" into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two. An alpha particle is identical to the nucleus of a helium ...

  8. Ionizing radiation - Wikipedia

    en.wikipedia.org/wiki/Ionizing_radiation

    Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. Alpha particle emissions are generally produced in the process of alpha decay . Alpha particles are a strongly ionizing form of radiation, but when emitted by radioactive decay they have low penetration power and can be absorbed ...

  9. Radium - Wikipedia

    en.wikipedia.org/wiki/Radium

    Activity 3300 Bq (3.3 kBq) Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium ...