What moves across axons

impulses

Explanation:

the long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells.

When a nerve impulse reaches the end of an axon, the axon releases chemicals called neurotransmitters. Neurotransmitters travel across the synapse between the axon and the dendrite of the next neuron.

Explanation:

Thats all i could think of