A water sample contains 0.1 M of Pb2+ and 0.1 M of Th4+ ions; when a solution of IO3– is slowly added to this sample, which of the ions will precipitate first and why?

Ksp Pb(IO3)2 = 2.5 × 10–13 and Ksp Th(IO3)4 = 2.4 × 10–15.

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

the answer to your question is c

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.