1. The problem statement, all variables and given/known data A 100W sodium lamp(lambda=589nm) radiates energy uniformly in all directions. (A) At what distance from the lamp will a totally absorbing screen absorb photons at the rate of 1.00 photon/cm2.s? (B) What is the photon flux on a small screen 2m from the lamp? 2. Relevant equations E=hf photon flux=#of photons/m2.s 3. The attempt at a solution I tried relating the area of the absorbing surface to the distance.