Question

With a long-lived daughter, isomeric transition occurs and a gamma ray is emitted. If the nucleus transfers energy to an electron, a conversion electron is emitted. What happens to Technetium?

A) Technetium undergoes isomeric transition and emits a gamma ray.
B) Technetium transfers energy to an electron and emits a conversion electron.
C) Technetium undergoes both isomeric transition and emits a conversion electron.
D) Technetium remains stable and does not undergo any decay.

Answer 1

Technetium-99m decays to technetium-99 by undergoing an isomeric transition that emits a gamma ray, or it can emit a conversion electron if the energy is transferred to an electron. The correct answer is C) Technetium undergoes both isomeric transition and emits a conversion electron.

Step-by-step explanation:

When technetium undergoes an isomeric transition, it emits a gamma ray and may transfer energy to an electron, resulting in the ejection of a conversion electron. Technetium-99m is a metastable isotope that decays to technetium-99 by emitting a gamma ray after about 6 hours. The emission of this gamma ray represents the nucleus transitioning from an excited (metastable) state to a more stable state. However, if during this process the nucleus transfers its excess energy to one of the inner electrons instead, this would result in the ejection of a conversion electron.

In the case of technetium-99m undergoing decay, it does both: it undergoes an isomeric transition and may also emit a conversion electron if the energy is transferred to an electron instead of being released as a gamma ray. Therefore, the correct answer is: C) Technetium undergoes both isomeric transition and emits a conversion electron.