Define mass defect and nuclear binding energy. For a nucleus `""_(Z)^(A)X`, write the value of mass defect and nuclear binding energy.

Explanation

### Step-by-Step Solution:

1. **Definition of Mass Defect:**
The mass defect of a nucleus is defined as the difference between the mass of the individual nucleons (protons and neutrons) that make up the nucleus and the actual mass of the nucleus itself. Mathematically, it can be expressed as:
\[ \Delta m = (Z \cdot m_p + (A - Z) \cdot m_n) - m_{\text{nucleus}} \]
where:
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