Final answer:
The phenomenon when light is scattered by colloid particles is called the Tyndall effect.
Step-by-step explanation:
The phenomenon that occurs when light is scattered by colloid particles is called Tyndall effect. This effect is named after the physicist John Tyndall who first studied it in the 19th century. When light passes through a colloid, such as a cloudy liquid or fog, it gets scattered by the suspended particles, making the path of the light visible.
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