The potential energy (y) curve for H₂ formation as a function of internuclear distance (x) of the H atoms is shown below.

The bond energy of H₂ is:

1. (b – a)
2. \(\frac{\left(\right. c - a \left.\right)}{2}\)
3. \(\frac{\left(\right. b - a \left.\right)}{2}\)
4. (c – a)