* Life is defined by certain characteristics: Living organisms exhibit characteristics like growth, reproduction, metabolism, response to stimuli, and adaptation.

* Molecules lack these characteristics: A molecule is simply a group of atoms bonded together. It does not grow, reproduce, metabolize, or respond to its environment in the way a living organism does.

Think of it this way: A brick is a building block of a house, but a brick alone is not a house. Similarly, a molecule is a building block of living organisms, but it is not alive on its own.