Ionizing a ground state hydrogen atom requires 2.179 × 10−18 J of energy. What wavelength of light is required to ionize hydrogen and in what region of the electromagnetic spectrum is it?

91.2 nm which in UV light region

Explanation:

Energy E = h v = hc / λ where h is Planck constant, c is speed of light and λ is the wavelength

λ = hc / E = (6.626 × 10 ⁻³⁴ × 3.0 × 10⁸) / 2.179 × 10−18 J = 9.12 × 10⁻⁸ m = 91.2 nm which in UV light region