Light with a wavelength of is just sufficient to cause photoemission from a surface

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Light with a wavelength of

450\,\text{nm}

is just sufficient to cause photoemission from a surface. What is the corresponding work function of the surface in joules? (a)

7.4\times10^{-20}\,\text{J}

(b)

4.4\times10^{-19}\,\text{J}

(c)

3.0\times10^{-19}\,\text{J}

(d)

4.4\times10^{-18}\,\text{J}