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.
Properties of Water--Notes. Water is a molecule made up of two hydrogen atoms and one oxygen atom. It has the formula H 2O. When. oxygen and hydrogen combine (H-O-H) they form a v-shaped triangular molecule. While water molecules. are electrically neutral, the oxygen atom holds a small negative charge and the two hydrogen atoms hold.