Consider the compounds tert-butylcyclohexane and 4-tert-butylcyclohexanol. Using silica gel plates, which of the two compounds will have the higher Rf value when ethyl acetate is the developing solvent?

4 tert-butylcyclohexane will have the higher Rf value when ethyl acetate is used as the developing solvent because the 4-tert-butylcyclohexanol is the more polar compound that can form hydrogen bonds with the polar silica gel stationary phase.

this means less polar 4-tert-butylcyclohexanol will have a higher Rf

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.