1 By comparison, machine shops also cut metal, but they are more concerned with the machining of parts on machine tools. 2  Firms that encompass both fab work and machining are also common. 3  Blacksmithing has always involved fabrication, although it was not always called by that name.
When water is in its solid state (ice) , the water molecules are packed close together preventing it from changing shape. Ice has a very regular pattern with the molecules rigidly apart from one another connected by the hydrogen bonds that form a crystalline lattice.
1 When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. 2  Solid water, or ice, is less dense than liquid water.  Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density.