Please help me! I will fan and metal!!
Using the conversion factor from eV (electron volts) to Joules, determine which energy level to another would show a line at 435 nm in an emission spectrum. Use the formulas and the energy level information below to answer the questions.
Needed constants:
1.00 eV=1.6x10^-19 J
C= 3.00 x10^8 m/s
n=6.63x10^-34 J*s
Energy level values: E6: E= -0.378 eV
E5: E=-0.544 eV
E4: E= -0.850 eV
E3: E= 1.51 eV
E2: E= -3.403 V
Yes, the last one only has a V.

Question

Please help me! I will fan and metal!!
Using the conversion factor from eV (electron volts) to Joules, determine which energy level to another would show a line at 435 nm in an emission spectrum. Use the formulas and the energy level information below to answer the questions. 
Needed constants: 
1.00 eV=1.6x10^-19 J 
C= 3.00 x10^8 m/s 
n=6.63x10^-34 J*s 
Energy level values: E6: E= -0.378 eV 
E5: E=-0.544 eV 
E4: E= -0.850 eV 
E3: E= 1.51 eV 
E2: E= -3.403 V 
Yes, the last one only has a V.

anonymous · Answer

For anyone that may wonder in the future, 
The conversion factor is 1.60x10^-19J/eV
The energy for the wavelength 435nm is E = hc/λ where h is Planck's constant =6.63x10^-34J
So E = 6.63x10^-34*3.00x10^8/435x10^-9 = 4.57x10^-19J
4.57x10^-19J*1eV/1.60x10^-19 = 2.86eV rounded to 2.9eV
This corresponds to a drop from n = 5 to n =2 (-0.5 + 3.4 = 2.9eV)
Is the answer.