The relative rates of reaction of ethane, toluene, and ethylbenzene with bromine atoms have been measured.
the most reactive hydrocarbon undergoes hydrogen atom abstraction a million times faster than does the least reactive one.

arrange these hydrocarbons in order of decreasing reactivity.

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .

Less stable  hope this

A.(nh4)(2co3)is the correct answer