Question

Electromagnetic radiation has an energy 14.4ev. To which region of electromagnetic spectrum belongs to_____
(1)
gamma γ - ray region

Answer 1

Answer:

Ultraviolet region

Explanation:

From Plancks law, the energy is E = hv  (v is frequency and h the Plancks constant 6.6 * 10⁻³⁴ ).

Also, 1 eV = 1.6 * 10⁻¹⁹J . SO, 14.4eV = 14.4 * 1.6 * 10⁻¹⁹

∴  v = E/h = 14.4 * 1.6 × 10⁻¹⁹ / (6.6 * 10⁻³⁴)    = 3.4×10¹⁵Hz .    

The range of frequency of ultraviolet rays varies from 5×10⁷Hz to 7×10¹⁴Hz. Hence, the given region belongs to ultraviolet region of electromagnetic spectrum.