How does heat affect the motion of atoms?

Due to heat , the kinetic energy of the atoms in the substance increases due to which they start vibrating vigorously and the inter-molecular attraction decreases and the substance increases in volume. For example, on boiling water...heat energy imparted makes the volume increase and finally turn into steam or water vapour in air.(The inter-molecular space in air is more than that in water.)

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 .