1.989 Ă— 10^30 kg The sun consists of about 70% hydrogen, 28% helium, 1.5% carbon, nitrogen and oxygen, and 0.5% all other elements. Additionally, the sun's mass is decreasing every second as it fuses 610 million metric tons of hydrogen into 606 million metric tons of helium each second for a loss of 4 million metric tons per second.