[单选题]
X-rays of wavelength o8 *52 zm-.7,mjn r 1ahophzs fkj/eyg0.20 nm are scyunh 1o1v(x4ya2a0bnhl 1k2a0 qp/oxattered by a metal. The wavelength shift is observed to 1 aaaq41 b10k0/y (hxyo 2u vonnx2phlbe $2.1 \times 10^{-12} \; m$ at a certain scattering angle measured relative to the incoming X-ray. What is the scattering angle?
A. $20^{\circ}$
B. $40^{\circ}$
C. $60^{\circ}$
D. $80^{\circ}$
Post time 2024-1-22 00:41:22