Final answer:
Ions are the electrically charged molecules that are involved in nerve impulses, which are created due to a difference in charge across a neuron's membrane.
Step-by-step explanation:
The electrically charged molecules involved in a nerve impulse are called ions. Nerve impulses are electrical phenomena that occur due to a difference in electric charge across the neuron's plasma membrane, and this difference is maintained by ions, which are electrically charged atoms or molecules. When an atom has more or fewer electrons than protons, it becomes an ion. This imbalance in charge is essential for the transmission of nerve impulses in neurons.