Classify the following as a physical or chemical change Change
Dry ice sublimates.
Mercury oxide decomposes into mercury and oxygen
Nail polish remover evaporates
Intermolecular forces are overcome between iodine molecules
Milk is heated to 40°C
Butter softens when heated
Sugar is ground to form icing sugar
Sugar caramelises during the making of fudge
Ice melts
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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 .

Its not chemical its not radiation and its not convection because there is not movement of fluids so it is thermal conduction