The increasing order (lowest first) for the values of `e//m` (charge//mass) for electron `(e)`, proton `(p)`, neutron `(n)`, and alpha particle `(alpha)` is

Options

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

Explanation

To determine the increasing order of the charge-to-mass ratio (e/m) for an electron, proton, neutron, and alpha particle, we can follow these steps:

### Step 1: Identify the charge and mass of each particle
- **Electron (e)**:
- Charge (q) = -1.6 x 10^-19 C
- Mass (m) = 9.11 x 10^-31 kg

- **Proton (p)**:
- Charge (q) = +1.6 x 10^-19 C
- Mass (m) = 1.67 x 10^-27 kg

- **Neutron (n)**:
- Charge (q) = 0 C
- Mass (m) = 1.67 x 10^-27 kg

- **Alpha Particle (α)**:
- Charge (q) = +3.2 x 10^-19 C (since it has 2 protons and 2 neutrons)
- Mass (m) = 6.64 x 10^-27 kg

### Step 2: Calculate e/m for each particle
- **Electron**:
\[ \frac{e}{m} = \frac{-1.6 \times 10^{-19}}{9.11 \times 10^{-31}} \approx -1.76 \times 10^{11} \text{ C/kg} \]

- **Proton**:
\[ \frac{e}{m} = \frac{1.6 \times 10^{-19}}{1.67 \times 10^{-27}} \approx 9.58 \times 10^{8} \text{ C/kg} \]

- **Neutron**:
\[ \frac{e}{m} = \frac{0}{1.67 \times 10^{-27}} = 0 \text{ C/kg} \]

- **Alpha Particle**:
\[ \frac{e}{m} = \frac{3.2 \times 10^{-19}}{6.64 \times 10^{-27}} \approx 4.82 \times 10^{7} \text{ C/kg} \]

### Step 3: Compare the values
- Electron: \(-1.76 \times 10^{11} \text{ C/kg}\) (most negative)
- Proton: \(9.58 \times 10^{8} \text{ C/kg}\)
- Neutron: \(0 \text{ C/kg}\)
- Alpha Particle: \(4.82 \times 10^{7} \text{ C/kg}\)

### Step 4: Arrange in increasing order
1. Neutron: \(0 \text{ C/kg}\)
2. Alpha Particle: \(4.82 \times 10^{7} \text{ C/kg}\)
3. Proton: \(9.58 \times 10^{8} \text{ C/kg}\)
4. Electron: \(-1.76 \times 10^{11} \text{ C/kg}\) (most negative)

### Final Answer
The increasing order of e/m for electron, proton, neutron, and alpha particle is:
**Neutron < Alpha Particle < Proton < Electron**