1.With the help of diagrams, differentiate between absorption and adsorption. (3) 2. What is the underlying principle of the BET technique? (2) 3.Compare and contrast between the BET and the Langmuir theory by completing the table below. (4) 4.Consider the XPS spectra of Ti and TiO2 below and explain, in no more than three sentences, the shift in the binding energy regions when moving from Ti to TiO2. (4) 5.What are Auger electrons? (5) 6.Label the diagram below. (4) 7.Use the diagram below to derive Bragg's Law