1) Write down expression for Klein-Gordon equation. Outline steps how to arrive to the expression starting from Einstein energy-momentum relationship. Explain why it is not providing consistent description of a single particle states for a relativistic system. 2) Write down expression for Dirac equation. Explain what are the solutions (the properties), introduce gamma matrices and use them to express Dirac equation in a different form. 3) Explain the problem with particle antiparticle representation using Dirac formalism. Why the Feynman-Stuckelberg interpretation was essential to complete theoretical description. 4) Explain the concept of helicity eigenstates. 5) In the formalism as above write down two discrete symmetry transformations, which correspond to charge conjugation and parity.