Which of the following statement about proton is correct?

Options

A. Proton is the nucleus of deuterium
B. Proton is an `alpha`- particle
C. Proton is an ionised hydrogen molecule
D. Proton is ionised hydrogen.

Explanation

To determine which statement about protons is correct, let's analyze each option step by step.

### Step 1: Analyze Option 1
**Statement:** Proton is the nucleus of deuterium.

- **Explanation:** Deuterium is an isotope of hydrogen that contains one proton and one neutron in its nucleus. Therefore, the nucleus of deuterium consists of both a proton and a neutron, not just a proton.
- **Conclusion:** This statement is incorrect.

### Step 2: Analyze Option 2
**Statement:** Proton is an alpha particle.

- **Explanation:** An alpha particle is the nucleus of a helium atom, which consists of 2 protons and 2 neutrons. Since a proton is a single positively charged particle, it cannot be classified as an alpha particle.
- **Conclusion:** This statement is also incorrect.

### Step 3: Analyze Option 3
**Statement:** Proton is an ionized hydrogen molecule.

- **Explanation:** A hydrogen molecule (H₂) consists of two hydrogen atoms, each containing one proton and one electron. Ionizing H₂ would mean removing an electron, resulting in two protons (one from each hydrogen atom). Thus, it does not equate to just one proton.
- **Conclusion:** This statement is incorrect.

### Step 4: Analyze Option 4
**Statement:** Proton is ionized hydrogen.

- **Explanation:** A hydrogen atom consists of one proton and one electron. When we ionize hydrogen, we remove the electron, leaving behind just the proton. Therefore, an ionized hydrogen atom is indeed just a proton.
- **Conclusion:** This statement is correct.

### Final Answer
The correct statement about protons is: **Proton is ionized hydrogen.**

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