# need help in quanta quarks question!! PLS HELP (1 Viewer)

#### erfanau123

##### Member
fusion of hydrogen atoms in the sun to form a helium nucleus can be represented by the equation$\bg_white _{1}^{2}\textrm{H} + _{1}^{2}\textrm{H}\rightarrow _{2}^{4}\textrm{He}$

calculate the mass defect of the event and the energy produced

(specimen 4 marks )

#### chloe555

##### New Member
so what don't you get about it? add up the individual masses of the protons, neutrons, and electrons on the left, then do the same for the right hand side, convert everything to amu. find the difference (this will be the mass defect) then use E=mc^2 to find the energy. all good?

#### packwolf

##### Member
They would have given you the actual masses of each.

#### erfanau123

##### Member
i tried and failed
i gave to 2 james ruse kids and they couldnt get it either

u try it dude!

#### erfanau123

##### Member
They would have given you the actual masses of each.
well they didnt , probs why its a 4marker

#### b3kh1t

##### Member
Are the answers by any chance 1.987 u mass defect and 1.7883x10^17 J??

oops forgot to use amu sorry

sorry wrong equation is the energy released 1850.89 MeV

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#### HyperComplexxx

##### ლ(ಠ_ಠ ლ)
1 amu = 1.661 × 10-27 kg
Mass of He = 4.003 amu = 6.647x10-27kg
Mass Proton = 1.673x10-27kg
Mass Neutron = 1.675x10-27kg

Mdefect = 2Mass Proton + 2Mass Neutron - Mass of He (there are 2 proton and 2 neutron in He)
= 4.9x10-29 kg
E = mchammer
= (4.9x10-29)(3x10^8)^2
= 4.41x10-12J ?

I am unsure of method to do it
EDIT2: Fixed it up a bit but probs wrong anyways

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#### weirdguy99

##### Member
Just do it all in kilograms, and convert to amu right at the end so you don't have to convert too much.

#### nichorowitz

##### Member
yo cbf working it out but because it is actually atoms
just use the amu mass off the periodic table. find the difference then multiple by 931.5
this binding energy in MeV
EDIT:
actually didnt realise it was deuterium. that makes it a lot harder

#### erfanau123

##### Member
1 amu = 1.661 × 10-27 kg
Mass of He = 4.003 amu = 6.647x10-27kg
Mass Proton = 1.673x10-27kg
Mass Neutron = 1.675x10-27kg

Mdefect = 2Mass Proton + 2Mass Neutron - Mass of He (there are 2 proton and 2 neutron in He)
= 4.9x10-29 kg
E = mchammer
= (4.9x10-29)(3x10^8)^2
= 4.41x10-12J ?

I am unsure of method to do it
EDIT2: Fixed it up a bit but probs wrong anyways

Lol dude, umm yeh i got what u got but 3.8x10^-12 is correct, apparently the questions fukd cause they usually give u all info

#### b3kh1t

##### Member
Sorry, is this the right answer; mass defect 0.0024 u and the energy released 2.24 MeV

damn, solutions lol

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#### weirdguy99

##### Member
Lol dude, umm yeh i got what u got but 3.8x10^-12 is correct, apparently the questions fukd cause they usually give u all info
The question isn't fucked..you get the nucleon mass of helium from the periodic table.

#### HyperComplexxx

##### ლ(ಠ_ಠ ლ)
nooo, why did i enter this thread.....
I feel uncomfortable for physics now

#### b3kh1t

##### Member
The question is stuffed, because the have to at least give you the mass of the deutrium, just realised, no need to worry Hypercomplexxx

#### weirdguy99

##### Member
The question is stuffed, because the have to at least give you the mass of the deutrium, just realised, no need to worry Hypercomplexxx
You find the mass of the deuterium by adding the constituent nucleons (2 protons + 2 neutrons for both nucleons).

Mass of helium is 6.646x10^-27
Mass of hydrogen is 6.688x10^-27
Defect is 4.2x10^-29

E=Defect x Light Squared
=3.8x10^-12J = 24 MeV

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#### b3kh1t

##### Member
You find the mass of the deuterium by adding the constituent nucleons (2 protons + 2 neutrons for both nucleons).
But you do not have the mass of the binding energy between them.

#### b3kh1t

##### Member
You find the mass of the deuterium by adding the constituent nucleons (2 protons + 2 neutrons for both nucleons).

Mass of helium is 6.646x10^-27
Mass of hydrogen is 6.688x10^-27
Defect is 4.2x10^-29

E=Defect x Light Squared
=3.8x10^-12J = 24 MeV
how did you get that mass, I got 6.699x10^-27 (4sig. fig.) by adding the mass of the extra neutron??

#### FCB

##### Emma Watson <3
He got it out of the successone book.

#### weirdguy99

##### Member
He got it out of the successone book.
I don't own the success one book.