Complex sentence: It is well known for instance that within a particular family of chemical compounds, especially of organic chemistry, that there are strong correlations between structurhe relationship between the number of carbons in alkanes and their boiling points.
Split into simpler sentences: It is well known for instance that within a particular family of chemical compounds, especially of organic chemistry, that there are strong correlations between structure and observed properties. A simple example is the relationship between the number of carbons in alkanes and their boiling points.