Step 1: Understand what molecular weight means. Molecular weight is a measure of how heavy a molecule is, which can be affected by the number of atoms and the type of atoms in the molecule.
Step 2: Know what a polymer is. A polymer is a large molecule made up of many smaller units called monomers, linked together in a chain.
Step 3: Recognize that increasing the molecular weight of a polymer means making the polymer chains longer. This can happen by adding more monomers to the chain.
Step 4: Understand viscosity. Viscosity is a measure of how thick or sticky a liquid is. Higher viscosity means the liquid flows less easily.
Step 5: Realize that longer polymer chains can get tangled up with each other. This entanglement makes it harder for the liquid to flow.
Step 6: Conclude that as the molecular weight of a polymer increases, the viscosity also increases because the longer chains create more entanglements.