Explanation:

Only code 3rd is correct.

• Semiconductors are materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most ceramics).
• Semiconductors can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide.
• They are also known as integrated circuits or more commonly just chips, they may be the tiniest yet most exacting product ever manufactured on a global scale.
• They have four valence electrons in their outermost orbit and are formed due to covalent bonding.
• Conductors are formed using metallic bonding and insulators are formed using ionic bonding.
• The valence and conduction band in a semiconductor are separated by a forbidden energy gap of 1.1eV.
• Resistance is high in semiconductors whereas it is very small in conductors and very high in insulators.
• Semiconductors have negative temperature coefficients (conductors - positive and insulators - negative).

Hence opton 3rd is correct.