Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 14
14. C and Si both have same lattice structure, having 4 bonding electrons in each. However, $C$ is insulator whereas $Si$ is intrinsic semiconductor. This is because :
[2012]
(a) In case of $C$ the valence band is not completely filled at absolute zero temperature.
(b) In case of C the conduction band is partly filled even at absolute zero temperature.
(c) The four bonding electrons in the case of $C$ lie in the second orbit, whereas in the case of Si they lie in the third.
(d) The four bonding electrons in the case of $C$ lie in the third orbit, whereas for Si they lie in the fourth orbit.
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Answer:
Correct Answer: 14. (c)
Solution:
- (c) Electronic configuration of ${ }^{6} C$
${ }^{6} C=1 s^{2}, 2 s^{2} 2 p^{2}$
The electronic configuration of ${ }^{14} Si$
${ }^{14} Si=1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{2}$
As they are away from Nucleus, so effect of nucleus is low for $Si$ even for $Sn$ and $Pb$ are almost metalic.
