Question

The energy of a photon of light of wavelength 450 nm is

Answer 1

E = Energy (joules) 
h = Planck's constant (6.626 *10^-34 J/s) 
c = the speed of light (2.997 *10^8 m/s) 
lambda = the wavelength of light (convert to meters) 

Of course if you want the answer in electron volts (eV) you have to convert it later. 

So, E = (6.626*10^-34 x 2.997*10^8)/450*10^-9

= 4.413*10^-19 Joules 

1 eV = 1.6*10^-19 Joules 

Therefore the energy of a photon with a wavelength of 450 nm 

= 2.76 eV
i hope this will help you

Answer 2

Hey!!

C= λv
C = speed of light
λ = wavelength
v = frequency

450 nm = 450 x 10-9 m
3.00 x 10^8 m/s = 450 x 10-9 m

v= 6.67 x 1014 Hz

E = hv
E = energy
h = planks constant
v = Frequency!!

E = 6.626 × 10-34 x 6.67 × 1014 1
E = 4.42 × 10-19 J

hope it helps ;)