The increasing order for the values of e/m (charge/mass) is

Options

A. e, p, n, `alpha`
B. `n, p, e, alpha`
C. `n, p, alpha, e`
D. `n, alpha, P, e`

Explanation

To determine the increasing order of the values of \( \frac{e}{m} \) (charge/mass ratio) for the particles: electron, proton, neutron, and alpha particle, we will follow these steps:

### Step 1: Identify the charge and mass of each particle
- **Electron**: Charge = \(-1.6 \times 10^{-19}\) C (considered as 1 unit for calculation), Mass = \( \frac{1}{1836} \) times the mass of a proton.
- **Proton**: Charge = \(+1.6 \times 10^{-19}\) C (considered as 1 unit), Mass = 1 (mass of a proton).
- **Neutron**: Charge = 0, Mass = 1 (mass of a proton).
- **Alpha Particle**: Charge = \(2 \times 1.6 \times 10^{-19}\) C (2 protons), Mass = 4 (mass of a helium nucleus, which consists of 2 protons and 2 neutrons).

### Step 2: Calculate the charge/mass ratio for each particle
1. **Electron**:
\[ \frac{e}{m} = \frac{1 \text{ unit}}{\frac{1}{1836} \text{ mass of proton}} = 1836 \frac{\text{units}}{\text{mass of proton}} \]

2. **Proton**:
\[ \frac{e}{m} = \frac{1 \text{ unit}}{1 \text{ mass of proton}} = 1 \frac{\text{unit}}{\text{mass of proton}} \]

3. **Neutron**:
\[ \frac{e}{m} = \frac{0}{1 \text{ mass of proton}} = 0 \]

4. **Alpha Particle**:
\[ \frac{e}{m} = \frac{2 \text{ units}}{4 \text{ mass of proton}} = \frac{1}{2} \frac{\text{units}}{\text{mass of proton}} \]

### Step 3: Compare the charge/mass ratios
- Electron: \(1836 \frac{\text{units}}{\text{mass of proton}}\)
- Proton: \(1 \frac{\text{unit}}{\text{mass of proton}}\)
- Neutron: \(0\)
- Alpha Particle: \(0.5 \frac{\text{units}}{\text{mass of proton}}\)

### Step 4: Arrange in increasing order
From the calculations:
1. Neutron: \(0\)
2. Alpha Particle: \(0.5\)
3. Proton: \(1\)
4. Electron: \(1836\)

Thus, the increasing order of \( \frac{e}{m} \) is:
\[ \text{Neutron} < \text{Alpha Particle} < \text{Proton} < \text{Electron} \]

### Final Answer
The increasing order for the values of \( \frac{e}{m} \) is:
\[ \text{Neutron} < \text{Alpha Particle} < \text{Proton} < \text{Electron} \]