Alpha particles are ...... times heavier (approximately) than neutron

Options

A. 2
B. 4
C. 3
D. 5

Answer

To determine how many times heavier alpha particles are compared to neutrons, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Composition of Alpha Particles**:
- An alpha particle consists of 2 protons and 2 neutrons. This is important because we need to know the total mass of the alpha particle.

2. **Calculate the Mass of the Alpha Particle**:
- The mass of an alpha particle (M_alpha) can be expressed in terms of the mass of protons (M_p) and neutrons (M_n):
\[ M_{\alpha} = 2M_{p} + 2M_{n} \]
- Since the mass of a proton and neutron are approximately equal (both are about \(1.67 \times 10^{-27}\) kg), we can express the mass of the alpha particle in terms of the mass of neutrons:
\[ M_{\alpha} = 2M_{n} + 2M_{n} = 4M_{n} \]

3. **Comparison of Masses**:
- Now that we have established that the mass of the alpha particle is 4 times the mass of a neutron, we can conclude:
\[ M_{\alpha} = 4M_{n} \]

4. **Final Answer**:
- Therefore, alpha particles are approximately **4 times heavier than neutrons**.

### Conclusion:
Alpha particles are 4 times heavier than neutrons.

---