Which statement best describes the difference between a polymer and a small molecule covalent compound?

Which statement best describes the difference between a polymer and a small molecule covalent compound?

• A. Long chains made of many monomers; high melting/boiling points; often insulators and flexible.
• B. Molecules with fixed low molecular weight; high volatility.
• C. Ionic lattices with strong electrostatic bonds.
• D. Gases at room temperature with no repeating units.

Answer: (A)

Polymers are giant covalent structures built from many repeating units (monomers) linked together into long chains. That sheer size and the abundance of interchain interactions give polymers distinctive properties compared with small covalent molecules: you usually need a lot of energy to break into them, so melting and boiling points are high, and the chains can move past each other, giving flexibility. Since most polymers don’t have charged particles moving freely, they tend to be insulators rather than conductors. The statement captures this contrast by saying long chains made of many monomers, high melting/boiling points, and insulators plus flexibility. Small covalent molecules, in contrast, have low molecular weight and weaker intermolecular forces, so they’re more volatile and melt/boil at lower temperatures. Ionic lattices and gases without repeating units don’t describe polymers, so they don’t fit as well.

Polymers are giant covalent structures built from many repeating units (monomers) linked together into long chains. That sheer size and the abundance of interchain interactions give polymers distinctive properties compared with small covalent molecules: you usually need a lot of energy to break into them, so melting and boiling points are high, and the chains can move past each other, giving flexibility. Since most polymers don’t have charged particles moving freely, they tend to be insulators rather than conductors.

The statement captures this contrast by saying long chains made of many monomers, high melting/boiling points, and insulators plus flexibility. Small covalent molecules, in contrast, have low molecular weight and weaker intermolecular forces, so they’re more volatile and melt/boil at lower temperatures. Ionic lattices and gases without repeating units don’t describe polymers, so they don’t fit as well.