140k views
2 votes
If an isotope with an atomic mass of 223 and an atomic number of 87 undergoes alpha decay, which of the following statements is not true about the daughter nuclide?

A. The atomic mass decreases by 4.
B. The atomic number decreases by 2.
C. The daughter nuclide is radium.
D. The daughter nuclide is an alpha particle.

1 Answer

4 votes

Final answer:

In alpha decay, the daughter nuclide has an atomic mass decreased by 4 and an atomic number decreased by 2 from the parent isotope. The daughter nuclide from an isotope with atomic mass 223 and atomic number 87 is not an alpha particle but the nuclide with atomic mass 219 and atomic number 85, which is not radium.

Step-by-step explanation:

When an isotope undergoes alpha decay, an alpha particle, which consists of 2 protons and 2 neutrons, is emitted. This results in the daughter nuclide having an atomic mass that is decreased by 4 and an atomic number that is decreased by 2 compared to the parent isotope. Therefore, we can infer that the daughter nuclide from an isotope with atomic mass 223 and atomic number 87 would have an atomic mass of 219 and an atomic number of 85.

The correct statements regarding the daughter nuclide produced from the alpha decay of the parent nuclide with atomic mass 223 and atomic number 87 are that:

  • The atomic mass decreases by 4, making the atomic mass of the daughter nuclide 219.
  • The atomic number decreases by 2, making the atomic number of the daughter nuclide 85.
  • The daughter nuclide is not radium (Radium's atomic number is 88).

The incorrect statement, which is D. The daughter nuclide is an alpha particle, confuses the particle emitted during the decay with the resulting daughter nuclide. The alpha particle is not the daughter nuclide but rather the particle that is emitted as the parent nuclide transmutes into the daughter nuclide.

User PJK
by
7.2k points