The number of half-filled orbitals in the sublevel d that has 8e- equals

Achemist attempts to separate barium ions from lead ions by using the sulfate ion as a precipitating agent. the ksp values of baso4 and pbso4 are 1.1 × 10−10 and 1.6 × 10−8 , respectively. what two sulfate ion concentrations are required for the precipitation of baso4 and pbso4 from a solution containing 0.099 m ba2+(aq) and 0.099 m pb2+(aq)? 1. 2.47501 × 10−9 m, 3.60002 × 10−7 m 2. 1.02154 × 10−9 m, 1.48587 × 10−7 m 3. 2.17763 × 10−9 m, 3.16746 × 10−7 m 4. 1.11111 × 10−9 m, 1.61616 × 10−7 m 5. 3.68485 × 10−9 m, 5.35977 × 10−7 m