Question

Why can thermonuclear fusion in stars occur even when the average thermal energy of particles is lower than required?

Options

• Some particles in the high-energy tail of the distribution can participate in fusion

• All particles in a star always possess exactly the same energy

• Gravity eliminates the electrostatic repulsion between nuclei in stellar cores

• The Coulomb barrier does not exist inside stars

Answer 1

In stars, not all particles have exactly the same energy. Even when the average thermal energy is lower, some particles in the high-energy tail of the distribution can participate in fusion. This is why thermonuclear fusion in the Sun can occur at about \[1.5 \times 10^{7}\] K.