Following is a property of p-type semiconductor

The correct answer is option 3. The place where the 4^th valence electron is missing is called hole.

The correct property of a p-type semiconductor is that the place where the 4th valence electron is missing is called a hole.

A p-type semiconductor is a type of semiconductor in which the majority charge carriers are holes. Holes are created when a doping atom, such as boron or gallium, is added to a pure semiconductor. The doping atom has fewer valence electrons than the semiconductor atoms, so it creates a vacancy in the valence band. This vacancy is called a hole, and it can move through the semiconductor by accepting an electron from another atom.

The other options are incorrect because:

• Each atom forms four covalent bonds. This is a general property of semiconductors, not just p-type semiconductors.
• Fifth electron is extra and becomes delocalized. This is a property of n-type semiconductors, not p-type semiconductors.
• Increase in conductivity is due to negatively charged electron. This is incorrect because the majority charge carriers in a p-type semiconductor are holes, which are positively charged.

Therefore, the correct property of a p-type semiconductor is 3. The place where the 4th valence electron is missing is called a hole.