Answer:
mercury (II) Bromide
Step-by-step explanation:
A small value of Ksp indicates a insoluble substance.
the solubility of mercury(II) bromide is 6.2 x 10-20
while that of thallium(II) sulfide is
6.0 x 10-22
from these values thallium sulfide has the smallest solubility which means it is highly insoluble in per liters of water.
while mercury (II) Bromide is more soluble.
there the answer is mercury (II) Bromide