Five basic three dimensional geometric forms commonly found in solids
A solid has a certain size and shape. Solids are the thickest forms of matter. All the molecules in a solid are tightly fitted together, so the molecules can't move around very much. Solids are made up of different parts or compounds. Unlike liquids or gases, solids retain the same shape. Examples: wood, rock, and metals. Other examples of solids are the computer, the desk, and the floor.
You can change the shape of solids, but not easily. You can change the shape of sheets of lumber by sawing it in half or burning it. How might you change the shape of a piece of gum? At room temperature and atmospheric pressure, many substances exist as solids. In the periodic table, there are two liquids and 11 gases; the remaining 96 elements are solids.
Solids have the property of retaining their shapes with or without a container. This occurs because solids have rigid structures. Solids differ from liquids in that the particles in liquids, while still stuck together, do have some freedom of motion. Solids differ from gases in that gas molecules really don't interact with each other much, flying all over the place. Based on the molecular or atomic arrangement solids are broadly classified into crystalline solids and amorphous solids. Crystalline solids are perfect solids but amorphous solids have liquid like properties.