This section considers some of the chemistry behind the colour of dyes and how the target material, for example a fibre, influences the method of dyeing and the dye used. A dye in solution is coloured because of the selective absorption of certain wavelengths of light by specific bonds in the molecule.
Cannot travel in vaccum. Sound is energy and it causes vibration, which travels in a medium. So imagine molecules transfering the energy (vibration) from source toward a particular direction. In water molecules are more rigid than in gas. So vibration is transferred faster.
The presence of hydrogen bonds also makes water molecules more 'sticky' or in scientific terms cohesive and adhesive. The small charges on the water molecules allows them to stick together which is why water has a 'skin' that small insects can walk on, and also explains why water can be sucked up a straw so easily.