# Calculate energy from an reaction [closed]

I'm trying to calculate the released energy from a reaction. The radioactive substance polonium decays according to this formula: $$^{210}_{84}\mbox{Po} \rightarrow \mbox{X}+^4_{2}\mbox{He}$$ At first I solved X to be: $^{206}_{82} \mbox{Pb}$

Now when I have the whole reaction, what formula should I use?

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## closed as too localized by Manishearth♦May 23 '13 at 21:09

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Someone could please edit the question and write the formulas, I couldn't – Tim Billström May 23 '13 at 9:20
Do you expect us to visit unknown, quite possibly malware-infected sites and do your work for you? Try harder. – Deer Hunter May 23 '13 at 10:28
have you thought of energy conservation given the special relativity relation of mass with energy? – anna v May 23 '13 at 11:41
@DeerHunter and the other downvoter: why such hostility to a new user? You could ignore the question after all. kudos to Nivalth for taking the risk you perceived in the link. – anna v May 23 '13 at 11:45
@annav - I could ignore the question but not the risk it may be posing to the unwary. To the OP and others: please do not use abbreviated links. There is enough space in the question. – Deer Hunter May 23 '13 at 12:55

## 1 Answer

The mass of the original polonium atom is 209.9828737(13)AU, while the mass of the lead atom is 205.9744653(13)AU and the mass of the helium is 4.00260325415(6)AU. The mass deficit gives you the amount of energy released.

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