Two atoms collide while moving in a dilute gas. The larger atom has a mass M1 = 6 Daltons and a speed v1 = 200 m/s, while the smaller has a mass M2 = 1 Daltons. During the collision both atoms simply bounce off each other. They do not change their speeds, but after the collision they each change their directions, bouncing in the indicated directions. Gravity can be ignored during the collision. What is the direction of the change in the momentum of the smaller atom? Use the letters from the compass rose below the figure to specify directions.