Chemistry
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.

I think this is the same question which I've answered. If not, repost at the top of the page.
http://www.jiskha.com/display.cgi?id=1327912087