Definition

1. Noun:
   • The lowest energy state of an atom or other particle: In physics, the "ground state" is the most stable, lowest-energy configuration that a quantum mechanical system (like an atom, molecule, or subatomic particle) can occupy. A system in its ground state has no excess energy to lose.

Usage

• The term is used primarily in the fields of quantum mechanics, atomic physics, and chemistry to describe the fundamental, unexcited condition of a system.
• It is often contrasted with "excited state," which refers to any state where the system has higher energy than the ground state.

Examples

• Noun:
  • When an electron absorbs energy, it can jump from the ground state to an excited state.
  • The stability of an atom is greatest when all its electrons are in the ground state.
  • Calculating the ground state energy of a molecule is a fundamental problem in quantum chemistry.

Advanced Usage

• "To be in the ground state": Describes a particle or system existing at its minimum energy level.
  • At absolute zero temperature, a system is expected to be in its ground state.
• "Ground state configuration": Refers to the specific arrangement of electrons in their lowest available orbitals for an atom.
  • The ground state configuration of carbon is 1s² 2s² 2p².

Variants and Related Words

• Excited State (n): Any state of a quantum system that has a higher energy than the ground state.
  • The laser works by stimulating electrons to drop from an excited state back to the ground state.
• Ground State Energy (n): The specific energy value associated with the ground state.
  • The ground state energy of the hydrogen atom is -13.6 electron volts.

Synonyms

• Basal state: A less common synonym emphasizing it as the base level.
• Lowest energy level: A descriptive phrase for the ground state.

Related Phrases

• Return to the ground state: The process where an excited system loses energy (e.g., by emitting a photon) to go back to the ground state.
  • The photon is emitted when the atom returns to the ground state.
• Ground state degeneracy: A situation where the ground state has the same energy for two or more different quantum configurations.
  • The researcher studied the ground state degeneracy of the novel material.

Noun

1. (physics) the lowest energy state of an atom or other particle