The symbol `""_(1)^(3)H` indicates that the given hydrogen atom has a mass number equal to ....... and atomic number equal to ......

Answer

To solve the question regarding the symbol `""_(1)^(3)H`, we need to understand what the numbers represent in the context of atomic structure.

### Step-by-Step Solution:

1. **Identify the components of the symbol:**
The symbol `""_(1)^(3)H` is written in a specific format where:
- The superscript (3) represents the mass number (A).
- The subscript (1) represents the atomic number (Z).

2. **Determine the mass number:**
The mass number (A) is the total number of protons and neutrons in the nucleus of an atom. In this case, the mass number is given as 3 (the superscript).

3. **Determine the atomic number:**
The atomic number (Z) is the number of protons in the nucleus of an atom. Here, the atomic number is given as 1 (the subscript).

4. **Conclusion:**
Therefore, for the hydrogen atom represented by `""_(1)^(3)H`:
- The mass number is equal to **3**.
- The atomic number is equal to **1**.

### Final Answer:
- Mass number = 3
- Atomic number = 1