(5) Radiant energy does not require a medium and can travel in a vacuum. ↑ ↑
(6) The exchange of radiant energy takes place through photons. ↑ ↑
(7) The electron absorbs photons until the transition to an unbounded electron. The electron emits photons on its way to the ground state. ↑ ↑
(8)…(10) Inneratomic Electron-Proton emission / absorption