`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

Options

A. In caseof C the valence band is not completaly 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 orbit.
D. The four bonding electrons in the case of C lie in the third orbit, whereas for Si they lie in the fourth orbit.

Answer

C

Explanation

The electronic configuration of carbon and silicon (Si) are as follows: `._(6)C^(12)=._(1)S^(2),2S^(2)2p^(2)`
`._(14)Si^(28) =._(1)S^(2),._(2)S^(2),._(2)p^(6) ._(2)p^(6),._(3)S^(2),._(3)p^(2)`
The four boundary electrons are close to nucleus for C and away from nucleus for Si. So effect of nucleus on boundary electrons is low on Si and high on C. Therefore,