The required energy to split up an Oxygen atom

[Gliese123]

Homework Statement

"Calculate how much energy that is required for a oxygen atom ¹⁶₈O to split it up into 4 α-particles"

The Attempt at a Solution

1: (8 * 1,00727646688)u + (8* 1,00866491578)u = 16,12753105 u
The first one is the Oxygen's 8 protons and the second one is its 8 neutrons.

2: ¹⁶O = 15,994915 u (Taken from a schedule)
We also have to discount the 8 electrons: 15,994915 u - (8 * 0,00054858) u = 15,99052636 u

3: 16,12753105 u - 15,99052636 u = 0,1370146888 u
That'd be the mass defect.

How do I then proceed? What should I do next? I'm a bit confused.
The answer is 14 MeV.
Thank you

 

[sabalo]

If I recall correctly, once you have obtained the mass defect, you should be multiplying by 931.5 to find the mass equivalent to the energy.

If I'm right, you've made a mistake somewhere. I'm on my iPod at the moment, so there isn't a great deal I can tell you, but when I get to a computer I'll look at it in more detail.

 

[tms]

Homework Statement

"Calculate how much energy that is required for a oxygen atom ¹⁶₈O to split it up into 4 α-particles"

The Attempt at a Solution

1: (8 * 1,00727646688)u + (8* 1,00866491578)u = 16,12753105 u
The first one is the Oxygen's 8 protons and the second one is its 8 neutrons.

2: ¹⁶O = 15,994915 u (Taken from a schedule)
We also have to discount the 8 electrons: 15,994915 u - (8 * 0,00054858) u = 15,99052636 u

3: 16,12753105 u - 15,99052636 u = 0,1370146888 u
That'd be the mass defect.

How do I then proceed? What should I do next? I'm a bit confused.
The answer is 14 MeV.
Thank you

What about the energy of the four alphas?

 

[Gliese123]

If I recall correctly, once you have obtained the mass defect, you should be multiplying by 931.5 to find the mass equivalent to the energy.

If I'm right, you've made a mistake somewhere. I'm on my iPod at the moment, so there isn't a great deal I can tell you, but when I get to a computer I'll look at it in more detail.

Thanks :P

 

[Gliese123]

What about the energy of the four alphas?

Yeah. It's that. I don't really know how to add their value to it :/

 

[tms]

Well, you can calculate it. And then you can compare it to oxygen.