A student conducting a photoelectric effect experiment shines light of variable frequencies on an unidentified photosensitive surface. For each frequency, the student records the corresponding stopping potential. The table below shows these data. Frequency of incident light (x 1014) Stopping potential (V) 11.7 2.6 10.7 2.1 9.8 1.8 9.0 1.5 8.3 1.1 6.7 0.5 Plot a graph of the data. (This does not need to be handed in)Plot a graph of the data. (This does not need to be handed in) From this graph, determine: (a) Planck's constant (2 marks) (b) the threshold frequency of the unidentified photosensitive surface (2 marks) (c) the work function of the unidentified photosensitive surface (2 marks) (d) Using these findings and the table below, identify the element that makes up the photosensitive surface. (1 mark) Be sure to show your work or include an explanation of how you found your answer. Element Work function (eV) Aluminium 4.1 Magnesium 3.7 Sodium 2.3