How many photons of light having a wavelength 400 nm are necessary to provide 1 J of energy?

What is the number of photon of light with a wvelengthof 4000 pm that provide 1 J of energy ?

Assume that 10^(-17) J of light energy is needed by the interior of the human eye to see an object . How many photons of green light (lambda = 495nm) are needed to generate this minimum energy . [h=6.6xx10^(-34) Js]

The number of photons of light having wave number 'x' in 10 J of energy source is :

An electron and a photon each have a wavelength of 1.00 nm. Find the kinetic energy of electron.

Calculate the mass of a photon of sodium light having wavelength 5894 angstrom and velocity 3 (10*8)ms-1.

An electron and a photon each have a wavelength of 1.00 nm. Find the energy of the photon?

An electron and a photon each have a wavelength of 1.00 nm. Find their momenta?

Two group (A and B) of bean plants of similar size and same leaf area were placed in identical conditions .GroupA was exposed to light of wavelength of 400-450 nm and group B to light of wavelength 500-550 nm.Compare the photosynthetic rate of the two groups giving reason.