Any part of an experiment that cannot be changed is considered to be a(n)

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 .

The correct answer should be "electrons orbit the nucleus in circular motions exactly as shown on the classic bohr model."

Use a magnet to separate iron, evaporate water, i'm not sure how to separate the other two i'm sorry but good luck

Answer(false);