Momentum is

Options

A. directly proportional to wavelength
B. inversely proportional to wavelength
C. equal to `lamda//2pi`
D. not related to wavelength.

Explanation

To solve the question "Momentum is", we need to analyze the relationship between momentum and wavelength based on the principles of quantum mechanics, specifically focusing on the de Broglie hypothesis.

### Step-by-Step Solution:

1. **Understanding Momentum**:
Momentum (p) is defined as the product of mass (m) and velocity (v) of an object. The formula is:
\[ p = mv \]

2. **De Broglie Hypothesis**:
According to Louis de Broglie, particles such as electrons exhibit both wave-like and particle-like properties. He proposed a relationship between the wavelength (λ) of a particle and its momentum.

3. **De Broglie Wavelength Equation**:
The de Broglie wavelength (λ) is given by the equation:
\[ λ = \frac{h}{p} \]
where \( h \) is Planck's constant.

4. **Rearranging the Equation**:
From the de Broglie equation, we can express momentum in terms of wavelength:
\[ p = \frac{h}{λ} \]

5. **Analyzing the Relationship**:
From the equation \( p = \frac{h}{λ} \), we can see that momentum (p) is inversely proportional to wavelength (λ). This means that as the wavelength increases, the momentum decreases, and vice versa.

6. **Conclusion**:
Therefore, the correct relationship is that momentum is inversely proportional to wavelength.

### Final Answer:
Momentum is inversely proportional to wavelength.