  Solutions of quaternionic quantum mechanics (QQM) are difficult to grasp,
even in simple physical situations. In this article, we provide simple and
understandable free particle quaternionic solutions, that can be easily
compared to complex quantum mechanics (CQM). As an application, we study the
scattering of quaternionic particles through a scalar step potential. We also
provide a general solution method for the quaternionic Schr\"odinger equation,
which can be applied to more sophisticated and physically interesting models.
