1. There is an one-dimensional lattice with lattice constant a as shown below. An atom transits from a site to a nearest-neighbor site every seconds. The probabilities of transiting to the right and left are p and q=1-p respectively. 2 X (a) Calculate the average position of the atom at the time t = Nr, where N1;
(b) Calculate the mean square value (z-7)2 at the time t. ​