Materials technology

Materials Technology

Assignment No. 1


Part 1

(i) Metallic Bond
Its is known that the atomic structure of any element is made up of a positively charged nucleus surrounded by electrons revolving at different distances. Metallic elements contain only one, two or three electrons in the outer shell and in this case the strength of the bond is relatively weak between the outer electrons and the nucleus.









(ii) Ionic Bond
This type of bond occurs between metallic and non-metallic elements. It is known that in non-metallic elements the outer shell contains a larger number of electrons than the metals. For example the outer shell of a chlorine atom contains seven electrons and there is a strong driving force to attract an electron to make a stable group of eight. When sodium with one valence electron and chlorine with seven electrons react, the sodium gives up its electron to form a stable outer shell of eight...