Since energy cannot be created nor destroyed, the change in energy of the electron must be equal to the energy of the emitted photon.
The energy of the emitted photon is given by:

where
h is the Planck constant
f is the photon frequency
Substituting

, we find

This is the energy given to the emitted photon; it means this is also equal to the energy lost by the electron in the transition, so the variation of energy of the electron will have a negative sign (because the electron is losing energy by decaying from an excited state, with higher energy, to the ground state, with lower energy)
All ions are atoms with a charge
Answer:
HELLO! I WILL EXPLAIN WHY GOLF BALLS HAVE DIMPLES.
Explanation:
DIMPLES ON A GOLF BALL CREATE A THIN BOUNDARY LAYER OF AIR THAT CLINGS TO THE BALL'S SURFACE. THIS ALLOWS THE AIR TO FOLLOW THE BALL'S SURFACE A LITTLE FARTHER AROUND THE BACKSIDE OF THE BALL, THEREBY DECREASING THE SIZE OF THE WAKE.
I AM SO SORRY ABOUT THE CAP LOCKS I THINK MY CAP LOCKS BUTTON IS PUSHED, AND IT IS NOT POPPING UP FOR SOME REASON.
ANYWAYS, HAVE A GREAT DAY!!!!!!