In this research, band structure and band gap energy of molybdenum disulfide is simulated by tight binding method. For this purpose, we assumed orbitals of Mo atom and orbitals of S atom to describe the near conductance and valence band states. The direct band gap, obtained by the nearest neighbor approximation, is equal to 1.85 eV. We used a semi classical approach by exploiting Hamiltonian matrix and perturbation theory to investigate the optical properties of single-layer MoS₂. Optical parameters such as imaginary and real part of dielectric function have been calculated via kramers-kronig transformation and the electron energy loss spectrum calculated and compared with experimental as well as first principle calculations. The numerical analysis in this paper has been carried out by coding in MATLAB. These studies are important since the monolayer MoS₂ has been envisaged for applications in the optoelectronic devices such as photo detectors, solar cells and light emitting diodes.