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

Options

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

Answer

To determine how many times heavier an alpha particle is compared to a neutron, we can follow these steps:

### Step 1: Understand the Composition of an Alpha Particle
An alpha particle is essentially a helium nucleus, consisting of 2 protons and 2 neutrons. Therefore, the mass of an alpha particle can be approximated as the sum of the masses of these nucleons.

### Step 2: Determine the Mass of an Alpha Particle
The mass of an alpha particle is approximately 4 atomic mass units (U). This is because:
- Each proton has a mass of approximately 1 U.
- Each neutron also has a mass of approximately 1 U.
Thus, the total mass of the alpha particle (2 protons + 2 neutrons) is:
\[ \text{Mass of Alpha Particle} = 2 \times 1U + 2 \times 1U = 4U \]

### Step 3: Determine the Mass of a Neutron
The mass of a neutron is approximately 1 atomic mass unit (U).

### Step 4: Calculate the Ratio of the Masses
To find out how many times heavier the alpha particle is than the neutron, we can set up the following ratio:
\[ \text{Ratio} = \frac{\text{Mass of Alpha Particle}}{\text{Mass of Neutron}} = \frac{4U}{1U} \]
When we simplify this, the units (U) cancel out:
\[ \text{Ratio} = 4 \]

### Step 5: Conclusion
From our calculations, we find that an alpha particle is approximately 4 times heavier than a neutron.

### Final Answer
Alpha particles are approximately 4 times heavier than neutrons.

---