Estimates suggest that the solar nebula contained approximately 2% of elements heavier than hydrogen and helium. This is often referred to as the "metallicity" of the solar nebula.
It's important to note that this is just an estimate, and the actual percentage could vary slightly. However, it's clear that the vast majority of the solar nebula's mass was made up of hydrogen and helium, the two lightest and most abundant elements in the universe.
