Question

what is the mass of a photon of sodium light with a wavelength of 5890 A°

Answer 1

Hello Dear :-)

We know the formula 

λ = h/mc

Where h is the plank constant  = 6.62 × 10⁻³⁴ . J-s
c = 3 × 10⁸ m/s
λ =5890 × 10⁻¹⁰ m.

Now put this value in the formula .

λ = h/mc 
5890 × 10⁻¹⁰ = 6.62 ×10⁻³⁴ /(m × 3 ×10⁸)
m = 6.62 × 10⁻³⁴ /(5890 × 10⁻¹⁰) (3 × 10⁸)
m=  6.62 ×10⁻³⁴/17670 × 10⁻² .

m= 3.74 × 10⁻³⁶




Hope it Helps. :-)