Radon (Rn) is a gas. Its nucleus decays with the emission of an alpha particle to form an isotope of polonium (Po) :
The masses of the particles are: The rest energy of a unified mass unit is 931.5 MeV. The kinetic energy of the ejected particles is

Question

Radon (Rn) is a gas. Its nucleus decays with the emission of an alpha particle to form an isotope of polonium (Po) : Radon (Rn) is a gas. Its nucleus decays with the emission of an alpha particle to form an isotope of polonium (Po) : The masses of the particles are: The rest energy of a unified mass unit is 931.5 MeV. The kinetic energy of the ejected particles is A) 6.26 MeV B) 6.16 MeV C) 6.04 MeV D) 6.61 * 10<sup>-3</sup> MeV E) 5.73 MeV

Radon (Rn) is a gas. Its nucleus decays with the emission of an alpha particle to form an isotope of polonium (Po) : The masses of the particles are: The rest energy of a unified mass unit is 931.5 MeV. The kinetic energy of the ejected particles is A) 6.26 MeV B) 6.16 MeV C) 6.04 MeV D) 6.61 * 10<sup>-3</sup> MeV E) 5.73 MeV

The masses of the particles are: Radon (Rn) is a gas. Its nucleus decays with the emission of an alpha particle to form an isotope of polonium (Po) : The masses of the particles are: The rest energy of a unified mass unit is 931.5 MeV. The kinetic energy of the ejected particles is A) 6.26 MeV B) 6.16 MeV C) 6.04 MeV D) 6.61 * 10<sup>-3</sup> MeV E) 5.73 MeV

The rest energy of a unified mass unit is 931.5 MeV. The kinetic energy of the ejected particles is

Quizplus · Accepted Answer

The initial mass (before decay) is 222.017570 u and the final mass (after decay) is 218.008966 u. The difference in mass between the initial and final states (including the alpha particle) is:

Δm = [222.017570 u - 218.008966 u - 4.002603 u] × 931.5 MeV/u
    = 6.1637 MeV

This is the total kinetic energy of the alpha particle and the polonium isotope after the decay. Since the polonium isotope is typically produced in an excited state, it will quickly release some of its excess energy in the form of gamma rays. Therefore, the kinetic energy of the alpha particle alone can be estimated as slightly less than 6.1637 MeV. The closest choice is B) 6.16 MeV.

Radon (Rn) Is a Gas