Question

which of the following best describes a polymer?
a large molecule composed of repeating subunits called monomers
a type of metal
a single molecule, like glucose

Explanation:

To determine the best description of a polymer, we analyze each option:

1. A polymer is defined as a large molecule made by linking many repeating subunits (monomers) together. For example, proteins are polymers of amino acids (monomers), and nucleic acids are polymers of nucleotides (monomers).
2. A "type of metal" is incorrect because polymers are typically organic (or sometimes inorganic like silicones) and not metals. Metals have different chemical and physical properties (e.g., metallic bonding, conductivity) distinct from polymers.
3. A "single molecule, like glucose" is incorrect. Glucose is a monomer (a simple sugar), while polymers are large molecules made of many monomers. For example, starch (a polymer) is made of many glucose monomers linked together.

So the correct option is the first one as it matches the definition of a polymer.

Answer:

A. a large molecule composed of repeating subunits called monomers