Our next experiment had us exploring the properties of river rocks. We started with a combination of river rocks that needed to be separated by particle size.
First, the kids took a closer look at a mixed heap of rocks.
We used the large-mesh screen to separate the large and small pebbles.
Next, we moved to a medium-mesh to separate the large gravel.
Finally, we used the small mesh to separate the small gravel. This step left us with only sand in the cup.
This was their finding: a pebble breaks into gravel. Gravel breaks into sand. They label each cup containing each size of rocks.
Then, Big Sister asked: "Can sand break into something smaller?" We had to give that a try. We used the spoon to mixed around the sand and discovered a layer of very thing dust like rock particles.
With the help of our fingers, we were able to pick up some silt. They added limo (silt) to their labeled cups.