Which of the following is the correct statement ?

Options

A. Hydrogen has the same I.E. as that of alkali metals
B. Hydrogen has strong tendency to gain one electron same as that of alkali metals
C. Hydrogen molecules is diatomic so are the halogens
D. Electron affinity of hydrogen is same as that of halogens

Answer

To determine which of the statements provided is correct, we will analyze each option step by step.

### Step 1: Analyze Option 1
**Statement**: Hydrogen has the same ionization energy as alkali metals.

**Analysis**:
- Hydrogen has an atomic number of 1 and possesses only one electron.
- This electron is strongly attracted to the nucleus due to the small size of the hydrogen atom.
- Alkali metals, on the other hand, have larger atomic sizes and their outermost electron is further from the nucleus, leading to lower ionization energy.
- Therefore, more energy is required to remove the electron from hydrogen than from alkali metals.

**Conclusion**: Option 1 is **incorrect**.

### Step 2: Analyze Option 2
**Statement**: Hydrogen has a stronger tendency to gain one electron, similar to alkali metals.

**Analysis**:
- Alkali metals typically lose one electron to achieve a noble gas configuration.
- Hydrogen, however, tends to gain one electron to achieve the helium configuration (1s²).
- Thus, hydrogen's behavior is more similar to that of halogens, which gain electrons, rather than alkali metals.

**Conclusion**: Option 2 is **incorrect**.

### Step 3: Analyze Option 3
**Statement**: Hydrogen molecule is diatomic, as are the halogens.

**Analysis**:
- Diatomic molecules consist of two atoms.
- Hydrogen exists as H₂, which is indeed a diatomic molecule.
- Halogens also exist as diatomic molecules (e.g., Cl₂, F₂, I₂).
- Both hydrogen and halogens are homonuclear diatomic molecules, meaning they are composed of two atoms of the same element.

**Conclusion**: Option 3 is **correct**.

### Step 4: Analyze Option 4
**Statement**: The electro affinity of hydrogen is the same as that of halogens.

**Analysis**:
- The electro affinity of hydrogen is positive (approximately +72.8 kJ/mol), indicating that energy is required to add an electron.
- In contrast, halogens have a negative electro affinity, meaning they release energy when gaining an electron.
- Therefore, the electro affinity values of hydrogen and halogens are not the same.

**Conclusion**: Option 4 is **incorrect**.

### Final Answer
The correct statement is **Option 3**: Hydrogen molecule is diatomic, as are the halogens.

---