Mendeleev is the scientist who first developed

the atomic model

the atomic theory

elements

the periodic table

Dmitri Mendeleev is the scientist who first developed the periodic table.

He is a Russian chemist and inventor who formulated the periodic law and created the periodic table of elements. He corrected some of the properties of the elements. Now, we can easily locate the elements we wanted to identify. With the help of Mendeleev, studying chemistry is not that difficult because he tried to simplify some of the concept that was complex before.

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 .