Excited state

Definition

An excited state refers to a higher energy level of an atom or nucleus compared to its ground state, where electrons or nucleons occupy the lowest possible energy levels. This elevated energy level occurs when energy is absorbed by the atom or nucleus, causing an electron to move to a higher orbital or a nucleon to occupy a higher energy state. The excited state is important as it often leads to various forms of decay or transition back to the ground state, such as gamma decay and internal conversion.

5 Must Know Facts For Your Next Test

1. An excited state occurs when an atom or nucleus absorbs energy from external sources, such as heat or radiation, causing transitions to higher energy levels.
2. In the case of excited nuclear states, the process can lead to gamma decay where the nucleus releases excess energy as gamma rays.
3. Excited states can be short-lived, with atoms often returning to their ground states by emitting photons or undergoing internal conversion almost immediately after excitation.
4. Different isotopes can have varying excited states, influencing their stability and decay pathways, making them important in fields like nuclear medicine and radiochemistry.
5. Understanding excited states is crucial for applications like laser technology and spectroscopy, where transitions between these states are manipulated for practical uses.

Review Questions

• How does an excited state differ from a ground state in terms of energy and stability?
  • An excited state differs from a ground state primarily in energy; while the ground state is the lowest energy configuration, an excited state represents a higher energy level achieved when an atom or nucleus absorbs energy. This results in decreased stability since atoms in excited states tend to release energy to return to their more stable ground state through processes like gamma decay or internal conversion. The contrast between these states is fundamental in understanding atomic and nuclear behavior.
• Discuss the processes involved when an atom transitions from an excited state back to its ground state, particularly focusing on gamma decay and internal conversion.
  • When an atom transitions from an excited state back to its ground state, it can do so through several processes, with gamma decay and internal conversion being prominent examples. In gamma decay, the excited nucleus releases energy as gamma radiation, which carries away excess energy without changing the number of protons or neutrons. In contrast, internal conversion involves the excited nucleus transferring its energy directly to an electron, ejecting it from the atom while allowing the nucleus to settle into a lower energy level. Both processes are critical for understanding nuclear stability and radioactivity.
• Evaluate the significance of excited states in practical applications such as nuclear medicine and spectroscopy.
  • Excited states hold significant importance in fields like nuclear medicine and spectroscopy due to their impact on how atoms interact with energy. In nuclear medicine, understanding how certain isotopes can achieve excited states allows for targeted therapies and imaging techniques, as these isotopes can be manipulated for diagnostic purposes. Similarly, in spectroscopy, measuring the wavelengths emitted during transitions from excited states helps identify substances and understand their properties at a molecular level. The manipulation of these transitions facilitates advances in technology and research across various scientific disciplines.

Related terms

ground state: The ground state is the lowest energy configuration of an atom or nucleus, where electrons or nucleons are in their most stable positions.

gamma decay: Gamma decay is a type of radioactive decay where an excited nucleus releases energy in the form of gamma radiation, transitioning to a lower energy state.

internal conversion: Internal conversion is a process where an excited nucleus transfers its energy directly to one of its own electrons, resulting in the ejection of that electron while the nucleus transitions to a lower energy state.