The Sun is overwhelmingly composed of:

* Hydrogen (H): Approximately 70.6% by mass

* Helium (He): Approximately 27.4% by mass

The remaining 2% is made up of heavier elements like oxygen, carbon, neon, iron, and others.

It's important to note that these percentages are by mass, not by number of atoms. Since hydrogen atoms are much lighter than helium atoms, there are actually many more hydrogen atoms than helium atoms in the Sun.