To calculate the energy required to ionize a hydrogen atom (H) from its ground state (n=1), you can use the formula for the energy difference between two energy levels in hydrogen:
E = -13.6 eV * (1/n²_final - 1/n²_initial)
In this case, you want to go from the initial state n=1 (ground state) to an ionized state, which means the final state is n=∞ (since the electron is completely removed). Plugging these values into the formula:
E = -13.6 eV * (1/∞² - 1/1²)
E = -13.6 eV * (0 - 1)
E = -13.6 eV * (-1)
E = 13.6 eV
So, it requires 13.6 electron volts (eV) of energy to ionize a hydrogen atom from its ground state (n=1).