1. The problem statement, all variables and given/known data This is a pretty simple problem... Yet I got the wrong answer.. Hmm... "Find the threshold frequency for a calcium surface whose work function is 3.33eV" W=3.33eV = 3.33eV * 1.6x10^-19 J = 5.33x10^19 J f = ? h=6.63x10^-34 J*S 2. Relevant equations f=W/h 3. The attempt at a solution f=(3.33eV)(1.6x10^-19 J) / (6.63x10^-34 J*S) = 8.04x10^14 Hz <- My answer The answer in book is 5.02 x10^14 Hz. Can anyone tell me what i'm doing wrong?