posted by Kyle .
A Be3+ ion absorbs a photon with a frequency of 7.31 × 1015 Hz. If the energy of the final state of the Be3+ ion was -3.88 × 10(-18) J, calculate the energy of the initial state. Express answer in scientific notation.
My work so far:
delta E = (h)(v)
delta E = (6.63*10^34 Js)*(3.88*10^15)
delta E = 4.846 * 10^-18J
delta E = Ef - Ei
(4.846*10^-18) = 3.88*10^-18 - Ei
Ei = 9.66*10^-19J
Is this correct? I get confused with the negative signs in the energy values.