Which of the following statements is false?

Options

A. Photon has momentum as well as wavelength
B. Splitting of spectral lines in electrical field is called Stark effect
C. Frequency of emitted radiation from a black body goes from a lower wavelength to higher wavelength as the temperature increases
D. Rydberg constant has unit of energy

Explanation

To determine which statement is false, let's analyze each option step by step:

1. **Statement 1**: "Photon has momentum as well as wavelength."
- Photons exhibit both particle-like and wave-like properties. This dual nature is a fundamental concept in quantum mechanics. Photons have momentum given by the equation \( p = \frac{E}{c} \), where \( E \) is energy and \( c \) is the speed of light. They also have a wavelength given by the equation \( \lambda = \frac{h}{E} \). Therefore, this statement is **true**.

2. **Statement 2**: "Splitting of spectral lines in an electric field is called Stark effect."
- The Stark effect refers to the phenomenon where spectral lines are split into multiple components in the presence of an external electric field. This is a well-known effect in atomic physics. Therefore, this statement is **true**.

3. **Statement 3**: "The frequency of emitted radiation from a black body goes from a lower wavelength to higher wavelength as temperature increases."
- A black body is an idealized physical object that absorbs all incident electromagnetic radiation. According to Wien's displacement law, as the temperature of a black body increases, the peak wavelength of emitted radiation decreases (not increases). This means that the frequency of emitted radiation actually increases as temperature increases. Therefore, this statement is **false**.

4. **Statement 4**: "Rydberg constant has unit of energy."
- The Rydberg constant is typically expressed in terms of energy (joules) when discussing the energy levels of electrons in atoms. The value of the Rydberg constant is approximately \( 2.179 \times 10^{-18} \) joules, which confirms that it has units of energy. Therefore, this statement is **true**.

Based on the analysis, the false statement is **Statement 3**.

### Summary of the Solution:
- Statement 1: True (Photon has momentum and wavelength)
- Statement 2: True (Stark effect is the splitting of spectral lines in an electric field)
- Statement 3: False (Frequency of emitted radiation increases with temperature, not decreases)
- Statement 4: True (Rydberg constant has units of energy)

**Final Answer**: Statement 3 is false.