Hydrogen has three isotopes (A),(B) and (C). If the number of neutron(s) in (A), (B) and (C) respectivley, are (x) ,(y) and (z), the sum of (x), (y) and (z) is

Answer

To solve the problem regarding the isotopes of hydrogen and the sum of their neutrons, we can follow these steps:

### Step 1: Identify the isotopes of hydrogen
Hydrogen has three isotopes:
1. Protium (¹H)
2. Deuterium (²H)
3. Tritium (³H)

### Step 2: Determine the number of neutrons in each isotope
The number of neutrons can be calculated using the formula:
\[ \text{Number of Neutrons} = A - Z \]
where \( A \) is the mass number (total number of protons and neutrons) and \( Z \) is the atomic number (number of protons).

- For Protium (¹H):
- Mass number \( A = 1 \)
- Atomic number \( Z = 1 \)
- Number of neutrons \( X = A - Z = 1 - 1 = 0 \)

- For Deuterium (²H):
- Mass number \( A = 2 \)
- Atomic number \( Z = 1 \)
- Number of neutrons \( Y = A - Z = 2 - 1 = 1 \)

- For Tritium (³H):
- Mass number \( A = 3 \)
- Atomic number \( Z = 1 \)
- Number of neutrons \( Z = A - Z = 3 - 1 = 2 \)

### Step 3: Calculate the sum of neutrons
Now, we can sum the number of neutrons from each isotope:
\[ X + Y + Z = 0 + 1 + 2 = 3 \]

### Final Answer
The sum of the number of neutrons in the isotopes of hydrogen (A, B, and C) is **3**.

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