chemistry
posted by schoolgirl .
Consider an electron in the ground state of hydrogen.
(a)What is the least amount of energy needed to excite the ground state electron in Joules?
(b) Is an electron in the ground state of hydrogen capable of absorbing a photon with energy of 1.38e18 Joules.

dE = 2.180E18(1/1  1/2^2)
Solve for dE for and electron moving from n = 1 to n = 2.
1.38E18 = 2.180E18 (1/1  1/x^2)
Solve for x. If x can be rounded (reasonably) to a whole number, yes. 
Thank you very much.