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.
All of these are gases and yet have much higher molecular weights than water does. However, none of these can hydrogen bond, and that is why they are gases, whereas water is a liquid. Of course, at high temperatures water is a gas (steam) and at low temperatures water is a solid (ice). See the Web Links for more information about intermolecular forces. Why is water at room temperature a liquid?