Question

A standing wave having 3 nodes and 2 antinodes is formed between two atoms separated by a distance of \( 1.21 \, \text{\AA} \). The wavelength of the wave is:

• A. \( 1.21 \, \text{\AA} \)
• B. \( 2.42 \, \text{\AA} \)
• C. \( 6.05 \, \text{\AA} \)
• D. \( 3.63 \, \text{\AA} \)

Hint:

For standing waves, use \( L = n\frac{\lambda}{2} \) where \( n \) is number of segments (or half-wavelengths).

Answer 1

The Correct Option is A

Number of segments = number of half wavelengths = number of antinodes = 2
So, distance = \( \frac{n\lambda}{2} \Rightarrow \lambda = \frac{2 \cdot 1.21}{2} = 1.21 \, \text{\AA} \)