Step-by-step explanation:
Low Density Polyethylene has the a lot of branching causing the inter molecular forces to be weak. Because of this reason it has low density. It has a density of 910.0 - 925 kg/m³.
High density polyethylene has a higher density than LDPE. It has lower level of branching causing it to have higher inter molecular forces. It has a density of 930 to 970 kg/m³.
Ultra High density polyethylene has long chains. The number of monomers per molecule is 700 and 1,800. It has a density of 928 - 941 kg/m³.