The Moon has a greater effect on the tides because, although it is much smaller than the Sun, it is much closer.  Which planet does the sun have the least gravity effect on Mars or Mercury?
Mars

However, the melanocytes of people with darker skin produce more melanin.  Since Kim has more melanin than Jennifer, when they lay out in the sun Jennifer's skin is darker or lighter than Kim's?
lighter

The more dense the medium, the slower the light moves.  If Mona shines a light through both wool and cotton and determines that cotton is less dense then wool, which material will the light move faster through wool or cotton?
cotton

Therefore, increasing the surface area of solid reactants increases the reaction rate.  If you keep something whole before putting it into water it will dissolve slower or faster?
slower