Science Fair Immersion

For Immersion this term I am doing a Science Fair Board. I am testing a candy waterfall, my main question is { Can solids flow like liquids ? }
Here is a link to my project planner
I am going to test how fast specific solids can flow compared to liquids.
Right now I am researching about if the weight of things would make them flow faster and also researching about my hypothesis which is: I predict that the heavier and smaller things would flow faster than the lighter things.