Why does sand go hard when you put water on it?

Question

Why does sand go hard when you put water on it?

Answer 1

It goes hard because you are packing the small particles are coming close together and the sand Obsorbs the water which makes it hard.

Answer 2

most likely the surface tension of the water provides binding between the grains.

This stops them moving freely and the water also adds some mass to the sand so its heavy as well.

I think .....

Answer 3

The water bridges the grains, providing a glue-like strength to the mass. Because the grains stick together, wet sand is stronger than dry sand, where there is no bridging between grains.

Answer 4

Sand is the same hardness wet or dry.  It is usually small grains of quartz (SiO2).  It has a hardness of 7 on the Moh's hardness scale and is quite inert.

Answer 5

ask your HEART why.