1. Hydrogen (H): This makes up about 70.6% of the Sun's mass. It is the primary fuel source for the Sun's nuclear fusion reactions.

2. Helium (He): This makes up about 27.4% of the Sun's mass. It is a byproduct of nuclear fusion, where hydrogen atoms are fused together to form helium.

3. Other Elements: The remaining 2% of the Sun's mass is made up of trace amounts of heavier elements like oxygen, carbon, neon, iron, and others.

It's important to note that:

* The Sun is not solid, but rather a plasma – a superheated state of matter where electrons are stripped from atoms, creating a mix of charged particles.

* These proportions are by mass, not volume. By volume, hydrogen makes up an even larger percentage of the Sun.

* The Sun's composition can vary slightly with depth, with the core having a higher concentration of heavier elements than the outer layers.

These elements and their proportions are crucial for understanding the Sun's energy production, its structure, and its evolution over time.