Answer: Hydrogen and Helium > Hydrogen compounds > Rocks > Metals
Explanation: The solar nebular system contains 98% Light Gases of both Hydrogen and Helium (produced in the Big Bang); followed by 1.4% of Hydrogen Compounds including water, methane, and ammonia; then followed by 0.4% of Rocks like Silicates; and lastly 0.2% of Metals including Iron, Nickel and Aluminium.