Final answer:
The ionisation energy of a hydrogen atom can be calculated using the equation E = -13.6 eV / n^2, where n is the principal quantum number of the electron's energy level.
Step-by-step explanation:
The ionisation energy of a hydrogen atom is the amount of energy required to remove an electron from the atom. The ionisation energy can be calculated using the equation E = -13.6 eV / n^2, where n is the principal quantum number of the electron's energy level.
For example, if the electron is in the ground state (n = 1), the ionisation energy would be -13.6 eV / 1^2 = -13.6 eV. If the electron is in the 4th excited state (n = 4), the ionisation energy would be -13.6 eV / 4^2 = -0.85 eV.
Therefore, the ionisation energy of a hydrogen atom depends on the energy level of the electron and can be calculated using the equation E = -13.6 eV / n^2.