When defining concentration during diffusion, what exactly are we
describing?
A. focus of a solvent
B. mass/volume of a solute
C. the mass of a solvent
D. the same equilibrium throughout a system

Label the following as inner or outer planets; a) has 67 moons made mostly of hydrogen and helium b) has rings c)no moons, high volcanic activity d) known as the red planet, has 2 moons e) very thin atmosphere, moons or rings