Question

Both sand and water take the shape of the container in which they are placed;yet sand is a solid while water is a liquid.Explain?

Answer 1

Sand "appears" to take the shape of the container, but in actuality it really does not.  There is enough space between the particles of sand, that it will not completely occupy the volume/space of the container.  The reason it appears to do so, and it appears to "flow" like water, is because even though sand is a solid, it is considered to be what is called "granular".  Granular solids are made up of very small solid particles.  The space between these particles is greater than that in a "regular" solid, and this is what allows it to look like it flows and takes the shape of the container.

Answer 2

sand is justified as a solid because a single particle of sand is almost impossible to break. even though many particles seem to flow, an individual particle maintains its shape and it's mass.
hence sand is solis