Arrange the events that are believed to have formed the hydrosphere in their order of occurrence. - precipitation in the form of rainfall
- boiling of water due to earth's enormous heat
- arrival of icy debris
- bombardment of comets and meteorites
- condensation of water vapor

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.