The carbon-14 in upper atmosphere is generated by the nuclear reaction.

Options

A. `N_7^14 + H_1^1 to C_6^14 + e_(+1)^0 + H_1^1`
B. `N_7^14 to C_6^14 + e_(+1)^0`
C. `N_7^14 + n_0^1 to C_6^14 + H_1^1`
D. `N_7^14 + H_1^3 + n_0^1 to C_6^14 + He_2^4`

Answer

**Step-by-Step Solution:**

1. **Understanding the Source of Carbon-14:**
Carbon-14 is a radioactive isotope of carbon that is formed in the upper atmosphere. It is produced through a nuclear reaction involving cosmic rays.

2. **Cosmic Rays and Their Interaction:**
Cosmic rays are high-energy particles that originate from outer space and collide with particles in the Earth's atmosphere. This collision produces high-energy particles, such as neutrons.

3. **Nuclear Reaction Involving Nitrogen:**
The primary reaction that generates Carbon-14 occurs when a neutron collides with a nitrogen-14 nucleus present in the atmosphere. The reaction can be written as:
\[ \text{^14_7N} + \text{^1_0n} \rightarrow \text{^14_6C} + \text{^1_1H} \]
Here, nitrogen-14 (with 7 protons and 7 neutrons) captures a neutron (with no charge) and transforms into carbon-14 (with 6 protons and 8 neutrons) and releases a proton (hydrogen-1).

4. **Result of the Reaction:**
The result of this nuclear reaction is the formation of Carbon-14 and a proton. This Carbon-14 then enters the carbon cycle, where it can be incorporated into living organisms.

5. **Conclusion:**
Therefore, the nuclear reaction that generates Carbon-14 in the upper atmosphere is the interaction of nitrogen-14 with a neutron, resulting in the formation of carbon-14.

**Final Answer:**
The nuclear reaction that generates Carbon-14 in the upper atmosphere is:
\[ \text{^14_7N} + \text{^1_0n} \rightarrow \text{^14_6C} + \text{^1_1H} \]

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