Liquids generally have a lower density than solids. But you must have observed that ice floats on water. Find out why.

Density of ice is less than the density of water. Even though ice is solid but it floats on water which is a liquid because ice has a such a crystalline structure in which all the bonds are arranged in such a way that they have more space between them though from the outside it looks solid and compact and thus its structure allows air to pass in it, thus decreasing the density of ice.