# Q of p+p reaction.

p+p -> deutron+positron+neutrino(e)

The question is how much energy is released?

$$Q=(m_{p}+m_{p})-(m_{d}+m_{e^+}+0.26MeV)=(938+938)MeV-(938+939+0.51+0.26)MeV<0$$

So I don't understand how can energy be relesed? I found that Q for that reaction is 1.442MeV. What am I doing wrong?

Hootenanny
Staff Emeritus
Gold Member
Note that md < mp + mn

What is the mass of deutron then? How can I calculate it, or where can I find that data?

malawi_glenn
Homework Helper
You should have data in your course book, and also in tables that you may use on exams etc. Here is some good internet rescourses:

http://nucleardata.nuclear.lu.se/database/masses/ [Broken]

The mass of the deutron is $$m_n + m_p - E_{Binding}$$

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Thank you.