24.8°.Light with a wavelength of lambda = 519 nm in air is incident on a block with a refractive index nb=1.22 at an angle of incidence theta 1 =24.8 degree

the refractive index of air is na =1.00 What is the angle of refraction of the ray as it enters the block? What is the wavelength of the light in the block? What is the frequency of the light inside the block?