(a) Find the de Broglie wavelength of electrons in a TEM operating at 100 kV (ignore relativistic correction). (b) Compare with green light (550 nm) and estimate the theoretical resolution gain. Solution: (a) λ = 1.227/√V nm = 1.227/√100000 = 1.227/316.2 ≈ 0.00388 nm ≈ 3.9 × 10⁻¹² m. (b) Ratio = 550 nm / 0.00388 nm ≈ 1.4 × 10⁵. The diffraction limit shrinks by roughly this factor: from ~250 nm (light) toward ~0.002 nm in theory. Real TEMs achieve ~0.1 nm because magnetic lens aberrations, not diffraction, become the limit — still 2500× better than light microscopes.