1. A polymer is a large molecule (macromolecule) composed of repeating structural units.They are connected by covalent chemical bonds.( structural unit is a building block of a polymer chain)
2. Natural polymer such as natural and cellulose, which is the main constituent of wood and paper
1.As darker colour are good absorbers of heat, they are also good absorbers of light.
2.The color of an object depends on the wavelengths of colors reflected from the object.
3.A red apple is red because red wavelengths in visible light are reflected and other wavelengths are absorbed.
4.In fact, if a red apple were to be illuminated by light that had no red wavelengths, the apple appear almost black.
5.We can see the red colour of apple as our eyes enables to detect the red frequency in visible light that reflected from the object to our eyes.
6.When a black object is illuminated by white light, all wavelengths are absorbed and none are reflected -- that's why the object appears black.
7.when light is absorbed by a black object, the energy carried by the light doesn't just disappear. Rather, it raises the energy of the object doing the absorbing.
8.The object, in turn, releases the absorbed energy by emitting longer wavelength, lower energy infrared (heat).
9.Light just doesn't disappear when it strikes a black object -- it's transformed into another kind of radiation that is either radiated from or retained within the black object.
10.This transformation of light into heat is in line to the law of conservation of energy.
11.The darker the object, the better its emission of heat because it is a better absorber of light.
12.Hence,the reason dark colors are dark is that they absorb light instead of reflecting it. Since light is energy, absorbing light makes something hotter.
