Q2Q QQ (1 Viewer)

[Menomaths]

2011 HSC question from Quanta to Quarks:

²³⁵₉₂U+¹₀n¹⁴⁰₅₆Ba+⁹²₃₆Kr+4¹₀n

Explain why energy is released in this reaction.

The answer says:

Energy is released because the mass of the products of this reaction is less than the mass
of the reactants.
This ‘missing’ mass is converted to energy through the equation E = mc

When I add up the mass of U and the neutron (I'm assuming I'm not supposed to add the mass of the neutron?) it equals the mass of RHS(including the 4 neutrons)

 

[Parvee]

uhm I'm pretty sure you're not meant to explicitly work out the energy released since they didn't give the exact masses of the isotopes ( if these were given you would find that the reactants>products)

So to answer it you know that for energy to be released the mass of reactants should be greater than the mass of products, and to work out the energy you use E=mc^2
Which is practically what the answers say

I think thats how you would answer it :L

 

[Menomaths]

Yeh, just realized I'm not supposed to add up the atomic masses because their rounded up ^.^ silly me

Thanks