(a) Based on the nature of intermolecular forces, classify the following solids:
Silicon carbide, Argon
(b) ZnO turns yellow on heating. Why?
(c) What is meant by groups 12-16 compounds? Give an example.

5 views

1 Answers

(a) Silicon carbide (sic)=Covalent or network
Argon-Molecular (non polar)
(b) When ZnO is heated, it loses oxygen
`ZnOtoZn^(2+)+(1)/(2)O_(2)+2e^(-)`
`Zn^(2+)` ions are entrapped in the interstitial voids and `e^(-)` s in the neighbouring interstitial voids to maintain electrical neutrality. this gives rise to metal excess defect. due to the presence of `e^(-)`s in voids, the colour is yellow.
(c) Semiconductors which are prepared by combination of elements of group 12 and group.

5 views