Kepler’s third law links how long an object takes to orbit to how far it is from the body it orbits. The essential idea is that the square of the orbital period (P^2) increases with the cube of the semi-major axis (a^3). For planets around the Sun, using years for the period and astronomical units for the distance, this becomes P^2 = a^3. This result comes from Newton’s law of gravitation: P^2 = (4π^2/G(M)) a^3, and with the Sun’s mass and those units, the constant is 1, so the simple form holds. The other options mix up the exponents or ignore the cubic relationship, which is why they don’t fit observed planetary orbits.

Water is polar because its electrons are shared unevenly. Oxygen is more electronegative than hydrogen, so it pulls electron density toward itself, giving the molecule a bent shape with a partial negative charge on the oxygen end and partial positive charges on the hydrogen ends. This creates a dipole moment, a situation where one side of the molecule is slightly negative and the other slightly positive. That separation of charge explains why water interacts strongly with other polar substances and ions, helping it dissolve many of them. The description of having a slightly negative side and a slightly positive side best captures this idea. The other statements—being nonpolar, having no charge separation, or being unable to dissolve polar substances—don’t fit water’s actual behavior.

Lithification is the process by which loose sediment becomes sedimentary rock through compaction and cementation. As layers accumulate, the weight of overlying material squeezes the grains, reducing pore space and driving out water. At the same time, minerals dissolved in groundwater precipitate and act as cement, binding the grains together. This combination—grains pressed together and glued by cement—solidifies the sediment into rock, like sandstone or limestone. This is distinct from melting rocks into magma (an igneous process), dissolution by acid (a weathering/chemical process), or metamorphism from heat (which changes minerals and texture under high temperature and pressure).

Sublimation is the process where a solid changes directly into a gas, skipping the liquid phase. In the hydrologic cycle, this happens when ice or snow is exposed to enough heat and certain atmospheric conditions, so the solid water transitions straight to water vapor. Evaporation is liquid to gas, occurring at the surface of bodies of water. Condensation is gas to liquid, forming clouds. Precipitation is water falling to Earth from the atmosphere, in liquid or solid form, and not a state change from solid to gas. So the transition described—solid water becoming water vapor directly—is sublimation. An example you might see is snow or frost rapidly disappearing on a sunny, windy, dry day.