[填空题]
When two moles of hy;qw ab hn3(txg 9sp)o9d2nk36mi)5mvnygs:vs eu :qjk+ 4nz f 7m7u c2drogen and one mole of oxygen react to form two moles of water, the energy released is 484 kJ. H7:: vc g2e7v6qi + u4dzmmn5 ymuk)k 3snjnfs2ow much does the mass of the elements decrease in this reaction?
$\Delta m$ = $\times 10^{-12} \, \text{kg}$
What % of the total original mass of the system does this mass change represent? $ \times 10^{-8}\%$
