How can a nucleus be described by particular values of A, Z and N ...

[faduma]

How can a nucleus be described by particular values of A, Z and N when the mass of the nucleus is not equal to Zmp + Nmn, where mp and mn are the masses of free protons and neutrons?
 a. A, Z and N have no intrinsic meaning.
  b. A, Z and N describe the number of particles of given types, but mass has no meaning when part of the mass is elsewhere in the universe. c. A, Z and N describe the number of particles an ideal rather than a real nucleus would have. d. A, Z and N describe the number of particles of given types in the nucleus, but not their masses in a bound state. e. A, Z and N describe the number of particles of given types in the nucleus since the missing mass consists of electrons that are also present in the nucleus.

Question 2

It is often possible to use atomic masses when calculating the binding energy of a nucleus. This is not true for calculating the Q value for the e+ decay process since
 a. the electron masses do not cancel.
  b. a positron is an antiparticle. c. the electron masses cancel.
  d. the mass of a positron cannot be neglected when compared to the mass of a nucleus.
  e. none of the above.

[jharrington11]

Answer to Question 1

D

Answer to Question 2

A

[faduma]

TYSM

[kthug]

Excellent