Please answer this physics question

1. An electron is in a 2-dimensional rectangular box with slides of length a = 1 . 10 9m. The initial state of the electron is given by (ng, ny) = (3, 1). After some time the electron emits a photon and the state changes to (1, 2). a) What is the energy Ey of the photon in eV? a a Useful numbers: me = 9.1 . 10-3 kg h = 6.63 -10-34 J.S 1 J = 6.24 1018 eV a = 1 - 10 9 m a) Ey