Compared to the masses of its separate protons and neutrons, the ...

[Charlie]

Compared to the masses of its separate protons and neutrons, the total mass of a stable nucleus is always
 
  A)
 
  less.
  B)
 
  the same.
  C)
 
  greater.
  D)
 
  zero.
  E)
 
  varies from atom to atom.

Question 2

When a positronium atom (electron + positron) decays, it emits two photons. What are the energies of the photons?
 
  A)
 
  0.511 MeV and 1.022 MeV
  B)
 
  0.225 MeV and 1.022 MeV
  C)
 
  0.225 MeV and 0.285 MeV
  D)
 
  0.256 MeV and 0.256 MeV
  E)
 
  0.511 MeV and 0.511 MeV

[micaelaswann]

Answer to Question 1

A

Answer to Question 2

E

[Charlie]

TYSM

[ricroger]

Excellent