The Sun doesn't burn hydrogen in the traditional sense of burning. It fuses hydrogen atoms together through nuclear fusion. This process converts about 600 million tons of hydrogen into helium every second.

Here's a breakdown:

* Fusion: The Sun's core is incredibly hot and dense, allowing hydrogen nuclei (protons) to overcome their electrostatic repulsion and fuse together.

* Energy release: This fusion process releases a tremendous amount of energy, mostly in the form of light and heat.

* Mass conversion: A small portion of the hydrogen's mass is converted into energy according to Einstein's famous equation E=mc².

So, while it's common to say the Sun "burns" hydrogen, it's more accurate to say it fuses hydrogen into helium, releasing energy in the process.