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ionistaion energy of H atom and energy released

for part a , the question want ionistaion energy ... why shouldnt it be H2 atom dissciate to become 2H+ ion? but the solution gives H+ + e- = H instead?

for part c , shouldnt the loss of mass from 10.0kg of LiD= 0.002988x(10^6)x10= 29.88kg?

then use E= mc^2 to proceed?

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Reply 1

Joinedup

It's asking about atomic hydrogen - single H atoms rather than molecular Hydrogen which is pairs of H atoms bonded together - afaik A level physics papers asking spectroscopy type questions about Hydrogen will be usually asking about atomic Hydrogen (especially when they mention atoms of hydrogen as is done in this question), atomic hydrogen is incredibly common in the universe and important to astronomical spectroscopy.

for part 2 - the mass loss must be less than the original mass - you can't come out with a negative mass, it's an absurd answer that should warn you that you've done something wrong and need to check your calculation.