In our Sun hydrogen is by far the most abundant element followed by helium. Those two together make up 99.9 percent by number of the total atoms in the Sun! When other stars are studied spectroscopically it is found that most stars are composed of around 70 percent hydrogen and 28 percent helium by mass, very similar to what we see in the Sun. Traces of other elements include: oxygen, carbon, nitrogen, silicon, magnesium, neon, iron, sulfur.