What is the difference between ground state and excited state ?

Hint: When a quantum mechanical system or particle is bound—that is, spatially constrained—it can only take on discrete energy values known as energy levels. Classical particles, on the other hand, can contain any quantity of energy. The word is most usually used to refer to the energy levels of electrons bound by the electric field of the nucleus in atoms, ions, or molecules, but it may also apply to energy levels of nuclei or vibrational or rotational energy levels in molecules. A system with such distinct energy levels is considered to have a quantized energy spectrum.

Complete answer: The ground state is the condition in which all electrons in a system (an atom, a molecule, or an ion) are at their lowest energy levels. Because the electrons are on a “zero” energy level, the ground state is known to contain no energy when contrasted to an excited state. The vacuum state is another name for the ground state. When an atom in the ground state is given energy, it can absorb it and shift to an excited state. However, the stimulated state has a shorter life span. As a result, the atom returns to its ground state, discharging the energy it has received. When contrast to the excited state, the ground state is more stable and has a longer lifespan. The distance between electrons and the atomic nucleus in ground state atoms is the shortest conceivable. The electrons are closer to the nucleus of the atom. The excited state of an atom is the state that has a greater energy than the atom's ground state. One or more electrons are not at their lowest energy level in this situation. By taking energy from the outside, electrons have progressed to a higher energy level. However, in order to transition to an excited state, the energy delivered must be equivalent to the energy difference between the two energy levels. Hence, excitation will not occur.


Note:
Ground State: The state in which all electrons in a system (an atom, molecule, or ion) are at their lowest conceivable energy levels is referred to as the ground state. Any state of the system that has a higher energy than the ground state is called an excited state.