`A` hydrogen-like atom has ground state binding energy `122.4eV`. Then :
(a). its atomic number is `3`
(b). an electron of `90 eV` can excite it to a higher state
(c). an `80 eV` electron cannot excite it to a higher state
(d). an electron of `8.2 eV` and a photon of `91.8 eV` are emitted when a `100 eV` electron interacts with it

Options

A. Its atomic number is 3
B. a photon of 90 eV can excite it to a higher state
C. a 80 eV photon cannot excite it to a higher state
D. to excite an `e^(-)` minimum 91.8 eV photon is required

Answer

A, C, D