Earth's lower atmosphere contains negative and positive ions that are produced by radioactive elements in the soil and cosmic rays from space. In a certain region, the atmospheric electric eld strength is 13-4me and the eld is directed vertically down. This eld causes singlyr charged positive ions, at a density of 534 cm'3. to drift downward and singly charged negative ions. at a density of 773 cm'3, to drift upward {see the gu re}. The measured conductivity ofthe air in that region is 2.59 x 10'1'!1 [Qml'j. Calculate [a] the magnitude of the current density and [b] the ion drift speed, assumed to be the same for positive and negative ions. {a} Number DDUOEKDDDDDOSM Units