At 200°C,hydrogen molecule have velocity 2.4 × 105 cm s-1. The de Broglie wavelength in this case is approximately
1Å
1000 Å
100 Å
10 Å
λ=hmv=6.6×10−27ergs2NA×2.4×105cms−1
Mass of 1 molecule of H2=26.02×1023=6.6×10−27×6.02×10232×2.4×105=8.27×10−9cm=0.8×10−8cm=0.8Å≈1Å