In an ionic compound, the size of the ions affects the internuclear distance (the distance between the centers of adjacent ions), which affects lattice energy (a measure of the force needed to pull ions apart). the lattice energy affects the enthalpy of solution, which can affect solubility. based on ion sizes, rank these compounds by their expected solubilities in water.
rbl
rbbr
rbcl
rbf

Ascientist wants to know how individual lions within a pride interact with each other in their own environment. to do this, the scientist sedates and tags all of the lions within a pride. then, he places several remotely-controlled video cameras near the lions' den and performs an observational field study. he collects continuous video footage over the span of one year, analyzes the video, and then forms conclusions based on his observations.