The Wizard's skill Electrocute is a bolt of chain lightning, which (without runes) hits one target, and can jump to two additional targets. There are numerous other skills that can hit multiple enemies - the Wizard's Shock Pulse, the Wizard's Disintegrate, and the Demon Hunter's Chakram are more examples. Also, some attacks hit the same enemy multiple times on a single use of the skill.
Does each "injuring" of an enemy generate an on-hit effect? How do multiple-hit or multiple-opponent-hit skills interact with on-hit effects like chance to stun, life on hit, and class resource generation?