posted by Mikaela .
I have no idea how to do this problem, and I've been searching through my book for an hour. Help please?
An energy of 2.0x10^2 kJ/mol is required to cause a cesium atom on a metal surface to lose an electron. Calculate the longest possible wavelength of light that can ionize a cesium atom. In what region of the electromagnetic spectrum is this radiation found?
How many kilocalories are released by freezing 4.6 moles of H20?
You are not likely to obtain an answer by piggy backed questions; I suggest you post a new question at the top of the board.
E = hc/wavelength
Substitute h, c, and E and solve for wavelength. E is the energy/atom; to obtain that use 200,000 J/mole and convert to an atom by dividing by 6.022E23.
Is that visible light? Convert to Angstroms. 1 A = 1E-8 cm and 4000-7000 A is visible.