A positively charged ion is released at the origin of a co-ordinate system. The entire space is filled with a uniform electric field directed along po

A positively charged ion is released at the origin of a co-ordinate system. The entire space is filled with a uniform electric field directed along positive x axis and a uniform magnetic field directed along positive z direction.
(i) Which`(x, y or z)` co-ordinate of the particle will always remain zero during its course of motion?
(ii) Which `(x, y or z)` co-ordinate of the particle will always be negative?
(iii) It is true to say that radius of curvature of the path of the particle is decreasing while its x co-ordinate decreases?
(iv) If the ion is negatively charged will its y co-ordinate ever become negative?