Question

The α decay of 226Ra, another isotope in the decay series of 238U, first recognized as a new element by the Curies poses special problems because its daughter is a radioactive noble gas. What is the daughter nuclide produced in the α decay of 226Ra?

a) 226Rn
b) 238U
c) 208Pb
d) 228Ra

Answer 1

The daughter nuclide produced in the α decay of 226Ra is radon-222 (222Rn). The correct option is A.

Step-by-step explanation:

The daughter nuclide produced in the α decay of 226Ra (radium-226) is radon-222 (222Rn), which is a radioactive noble gas. During α decay, the parent nucleus loses an α particle, which consists of 2 protons and 2 neutrons, resulting in a decrease of the atomic mass number by 4 and the atomic number by 2.

In the case of 226Ra, the α decay leads to the formation of radon-222 since this nuclide's alpha decay reduces its atomic number from 88 (Ra) to 86 (Rn), and the atomic mass from 226 to 222. Therefore, the correct answer from the choices provided is a) 226Rn.