Bromine, a liquid at room temperature, has a boiling point of 58°c and a melting point of –7.2°c. bromine can be classified as a
compound.
impure substance.
mixture.
pure substance.

Pure substance

This is because the boiling point and melting point of bromine are correct.

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 .

What are the choices?