The NaCl molecule has a bond energy of 4.26eV; that is, this energy must be supplied in order to dissociate the molecule into Na and Cl atoms. Required:
a. What are the minimum frequency and maximum wavelength of the photon necessary to dissociate the molecule?
b. In what part of the electromagnetic spectrum is this photon?

Consider a file currently consisting of 200 blocks. assume that the file control block (and the index block in the case of indexed allocation) is already in memory. calculate how many disk i/o operations are required for contiguous, linked, and indexed (single-level) allocation strategies, for each of the conditions listed below. in the contiguous-allocation case, assume that there is not room to grow at the beginning but there is room to grow at the end. also assume that the block information to be added is stored in memory.