Size of neucleus increases from protium to tritium so in `H_(2),D_(2)&T_(2)` area off overlapping also increases in the same order.
Q. Which overlapping is responsible for bond formation in `H_(2),D_(2),T_(2)` respectively?

Options

A. 1s-1s in each
B. 2s-2s in each
C. 1s-2s in each
D. 1s-2s I `T_(2)`, 1s-1s in rest

Answer

To solve the question regarding the overlapping responsible for bond formation in \( H_2 \), \( D_2 \), and \( T_2 \), we will go through the following steps:

### Step 1: Identify the Isotopes
- **Hydrogen Isotopes**: The question involves three isotopes of hydrogen:
- Protium (\( H \)): Atomic mass = 1
- Deuterium (\( D \)): Atomic mass = 2
- Tritium (\( T \)): Atomic mass = 3

### Step 2: Understand the Electron Configuration
- All three isotopes have the same electronic configuration because they all have one electron in their outer shell:
- \( H \): 1 electron
- \( D \): 1 electron
- \( T \): 1 electron

### Step 3: Determine the Type of Overlapping
- The bond formation in these molecules involves the overlapping of atomic orbitals. In the case of \( H_2 \), \( D_2 \), and \( T_2 \):
- **For \( H_2 \)**: The overlapping occurs between the 1s orbitals of two hydrogen atoms.
- **For \( D_2 \)**: The overlapping occurs between the 1s orbitals of two deuterium atoms.
- **For \( T_2 \)**: The overlapping occurs between the 1s orbitals of two tritium atoms.

### Step 4: Conclusion on Overlapping
- In all three cases, the overlapping responsible for bond formation is the same:
- **Overlapping in \( H_2 \)**: \( 1s \) - \( 1s \)
- **Overlapping in \( D_2 \)**: \( 1s \) - \( 1s \)
- **Overlapping in \( T_2 \)**: \( 1s \) - \( 1s \)

### Final Answer
The overlapping responsible for bond formation in \( H_2 \), \( D_2 \), and \( T_2 \) is \( 1s \) - \( 1s \) in each case.

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