Give reason : (i)ZnO crystal on heating acquires the formula Zn_(1+x)O. (ii)There is an increase in conductivity when Silicon is doped withPhosphorus.

Give reason : (i)ZnO crystal on heating acquires the formula Zn_(1+x)

1.	Give reason : (i)ZnO crystal on heating acquires the formula Zn_(1+x)O. (ii)There is an increase in conductivity when Silicon is doped withPhosphorus.
Answer» Solution :(i)On heating ZnO loses oxygen as `ZnO to Zn^(2+) + 1/2 O_2 + 2e^-` Excess `Zn^(2+)` IONS are entrapped into vacant interstitial sites. Hence, there is metal excess. (ii)Silicon belongs to Group 14 while phosphorus belongs to Group 15. Hence, in the valence SHELL, P has one EXTRA ELECTRON than Si. When Si is replaced by P atom, due to extra electron, there is increase in conductivity.