The luminosity of the Sun is 4 x 1026 W, which means that the sun emits 4 x 1026 J of energy every second. How much mass does it change into energy every second? Express your answer in kilograms. In fusion reactions, only a small fraction of the hydrogen mass is converted into energy. 99.3% of the hydrogen is converted into helium, and just 0.7% of the hydrogen is converted into energy. Based on this information, how much hydrogen undergoes fusion in the Sun every second? Express your answer in kilograms.