42. We assume the neutrino has negligible mass. The photons, of course, are also taken to have zero mass.

Q

1

=

(2m

p

− m

2

− m

e

)c

2

= [2(m

1

− m

e

)

− (m

2

− m

e

)

− m

e

]c

2

=

[2(1.007825 u)

− 2.014102 u − 2(0.0005486 u)](931.5 MeV/u)

=

0.42 MeV

Q

2

=

(m

2

+ m

p

− m

3

)c

2

= (m

2

+ m

p

− m

3

)c

2

=

(2.014102 u) + 1.007825 u

− 3.016029 u)(931.5 MeV/u)

=

5.49 MeV

Q

3

=

(2m

3

− m

4

− 2m

p

)c

2

= (2m

3

− m

4

− 2m

p

)c

2

=

[2(3.016029 u)

− 4.002603 u − 2(1.007825 u)](931.5 MeV/u)

=

1

2.86 MeV .