Answer:
Shale is composed of small particles of clay. It's grain size is not visible, soft, and is generally impermeable.
Sandstone is composed of well-sorted sand-size quartz grains. It is very hard, the grain is visible.
Conglomerate is composed of assorted grain sizes. It's very poorly sorted and can be composed of more than one mineral and rock type.
I hope this helps.
Explanation:
