Question 5 week 2,3,4

[IsisGutierrez 1B]

Hello I need help on question 5 of this weeks achieve. I keep getting it wrong and I have no idea why. I have done this problem already a lot of times and still end up with the same answer. Please help. Below I attached the question and my work.

[Jasmine Hwang 2I]

Hello! You must multiply the enthalpy of fusion of water by the given mass of ice needed to be melted, in this case 409 g. This would provide you with a Joules value. You then divide this value by the value you got through the E = hc/wavelength formula. This formula gives you the energy per photon (J/photon). Therefore, by dividing the first Joule value by this E(photon) value, you will end with just the amount of photons. J divided by J/photon = Photons. Hope this helps!