Scientific Notation

In a semiconductor, when an electron gains enough energy, it can leave its covalent bond and become free, leaving behind a "hole." This hole behaves as a positive charge carrier, as the absence of an electron in a covalent bond creates a deficit of negative charge. The hole can move through the semiconductor when neighboring electrons fill the gap. Thus, a positive hole is essentially a vacancy created when an electron leaves its covalent bond, and it acts like a positive charge carrier in the material.

The correct answer is (B) : A vacancy created when an electron leaves a covalent bond.