Neutron are present in all atoms except

Options

A. He
B. C
C. H
D. N

Explanation

To solve the question regarding which atom does not contain neutrons, we will analyze the atomic structure of the given elements: Helium, Carbon, Hydrogen, and Nitrogen.

**Step 1: Understand the concept of neutrons in atoms.**
- Neutrons are neutral particles found in the nucleus of an atom. The number of neutrons can be calculated using the formula:
\[ \text{Number of Neutrons} = A - Z \]
where \( A \) is the atomic mass (number of protons + number of neutrons) and \( Z \) is the atomic number (number of protons).

**Step 2: Analyze Helium.**
- Atomic mass of Helium (A) = 4
- Atomic number of Helium (Z) = 2 (since Helium has 2 protons)
- Calculation:
\[ \text{Neutrons in Helium} = 4 - 2 = 2 \]
- Conclusion: Helium has 2 neutrons.

**Step 3: Analyze Carbon.**
- Atomic mass of Carbon (A) = 12
- Atomic number of Carbon (Z) = 6 (since Carbon has 6 protons)
- Calculation:
\[ \text{Neutrons in Carbon} = 12 - 6 = 6 \]
- Conclusion: Carbon has 6 neutrons.

**Step 4: Analyze Hydrogen.**
- Atomic mass of Hydrogen (A) = 1
- Atomic number of Hydrogen (Z) = 1 (since Hydrogen has 1 proton)
- Calculation:
\[ \text{Neutrons in Hydrogen} = 1 - 1 = 0 \]
- Conclusion: Hydrogen has 0 neutrons.

**Step 5: Analyze Nitrogen.**
- Atomic mass of Nitrogen (A) = 14
- Atomic number of Nitrogen (Z) = 7 (since Nitrogen has 7 protons)
- Calculation:
\[ \text{Neutrons in Nitrogen} = 14 - 7 = 7 \]
- Conclusion: Nitrogen has 7 neutrons.

**Final Conclusion:**
Among the options provided, the atom that does not contain any neutrons is **Hydrogen** (Option C).

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