Difference WikiChemistry

Difference Between Ground State and Excited State

Main Difference

The main difference between Ground State and Excited State is that in an atom Ground State is a state where electrons are found at their lowest energy levels, whereas at Excited State, the electrons in that atom contain higher energy than the ground state.

Ground State vs. Excited State

The ground state is the state where electrons contain the lowest energy in an atom, but the excited state is the state where electrons have higher energy than the ground state. At the ground state, a system is said to have zero energy; on the flip side, at an excited state, a system is said to have higher energy.

ADVERTISEMENT

Ground state electrons are highly stable and can remain in the state as long as the atom is stable; on the contrary, electrons at excited state are highly unstable. The ground state electrons have a higher lifetime, but excited state electrons have a shorter lifetime.

For electrons at the ground state, the distance between that electron and the nucleus is the minimum and the shortest distance; however, an excited state, the distance between the electron and the nucleus is higher. At the ground state, the electrons are located at their lowest energy levels, whereas at excited state, the electrons are located at higher energy levels.

An electron has to lose energy in the form of photons to come to a closer and lower energy level to reach the ground state, but to reach an excited state, an electron is excited and given energy, and thus, it leaves the lowest energy level for a higher energy level.

ADVERTISEMENT

Comparison Chart

Ground StateExcited State
The state where electrons contain the lowest energy in an atomThe state where electrons have higher energy than the ground state
Stability
Highly stableLess Stable
Lifetime
Retain for a longer periodRetain for the shorter period
Energy
Zero energyHigh energy
Distance from Nucleus
Closest possible distanceHigher distance
Location of Electrons
Lowest possible energy levelsHigher energy levels
Procedure
An electron releases energy for coming to the Ground stateAn electron absorbs energy to go to an excited state.

What is Ground State?

The ground state is referred to as the state in which all components of an atom are found in their lowest possible energy levels. Therefore, at Ground state, a system is said to have zero energy state where electrons zero energy and are found to be more stable.

ADVERTISEMENT

It is a state where electrons contain the lowest energy in an atom and can remain in the state as long as the atom is stable. Thus the atom does not go back to any further state and rather remain in the ground state. This is the reason which leads to a higher life for electrons at the ground-state. Another term for the ground state concerning quantum field theory is a vacuum state.

Some atoms may have different capabilities for their tendency to be in a ground state or excited state as some of the atoms and molecules contain more than one ground state. Some of these have two ground states, where the electrons find themselves stable.

For atoms that have two ground states, have a particular atom is known as degenerate. For example, in the case of hydrogen, there are two ground states and are known degenerate. The degeneration of an atom or molecule is led by the commute of a non-trivial unitary operator with Hamiltonian with a particular system. For systems that contain lower temperatures or zero temperatures are known to be in the ground state.

For electrons at Ground state, the distance between that electron and the nucleus is the minimum and the shortest distance due to their location in that atom as the lower energy levels are closer to the nucleus. Thus stable energy electrons are found in those levels, i.e., these electrons are located in their lowest energy levels.

To reach Ground state if electrons are already at the excited state by absorbing the energy. These electrons thus lose energy in the form of photons to come to a closer and lower energy level. At this moment, there are a few examples of the elements and their relative ground state configuration. As in Lithium, the ground state configuration would be 1s22s1.

What is Excited State?

The excited state conversely is referred to as the state in which all components of an atom are found in higher energy levels as compared to the lower energy levels of the ground state. Thus at excited state, a system is said to have a higher energy state where electrons have higher energy and thus are found to be less stable. Thus at this energy level in an atom, these electrons cannot remain in the state long and are found to release their energy to get to a stable state.

The excited state always tends to lose its energy to go to a ground state. This is because, in an excited state, these electrons will adjust their energy. It will go back to a lower energy state by losing their energy, which it had absorbed at the ground state to go to an excited state. This process of losing energy and getting back to the ground state is known as decay, and this is the reason for the shorter lifetime of these excited state electrons.

The atoms that are at the ground state are excited by using energy; this energy to excite an electron should be equal to the difference between the two energy levels. If less, the excitation process will not complete, and the electron will remain at that energy level.

For electrons at excited state, the distance between the electron and the nucleus is higher as the shells where these electrons are located are found in the outer regions. Thus higher energy electrons are found in those levels concerning their location in higher energy.

An electron has to gain energy to reach an excited state. Thus after gaining energy, they shift to higher energy levels from a lower energy level. At this moment, the example of lithium concerning their relative excited state configuration. In Lithium, the excited state configuration would be 1s23p1.

Key Differences

  1. The ground state is the state where electrons contain the lowest energy in an atom, but on the contrary, an excited state is a state where electrons have higher energy than the ground state.
  2. To reach the ground state, an electron has to lose energy to come to a lower energy level; on the flip side, to reach an excited state, an electron is excited to leave the lowest energy level for a higher energy level.
  3. The ground state method is said to have zero energy; on the flip side, the excited state system is said to have higher energy.
  4. Ground state electrons are highly stable; however, electrons at excited states are highly unstable.
  5. The ground state electrons have a higher lifetime; conversely, excited state electrons have a shorter lifetime.
  6. Electrons at Ground state have a minimum distance from the nucleus; however, an excited state, the distance between the electron and the nucleus is higher.
  7. At the ground state, the electrons are located in their lowest energy levels; on the other hand, at excited state, the electrons are located at higher energy levels.

Conclusion

The ground state is the state where electrons contain the lowest energy in an atom and tend to be highly stable, but the excited state is the state where electrons have higher energy than ground state and have lower stability.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss