Answer:
True.
Step-by-step explanation:
At the axon tips, there are vesicles containing chemicals called neurotransmitters (NT). On the arrival of the electrical impulse, calcium ions enter and stimulate the release of those NT via exocytosis into the synaptic cleft.
The NT will diffuse across the cleft and bind to specific receptors on the post-synaptic membrane to initiate an action.