Question

Calculate the energy and frequency of red light having a wavelength of 6.55 x 10⁻7m.

Answer 1

Answer:

E = 3.035× 10-¹⁹J = 1.9eV

f = 4.58 × 10¹⁴Hz

Explanation:

wavelength = 6.55 × 10-⁷m

c = 3 × 10⁸m/s

f = ?

E = ?

a) f = c/wavelength

f = 3 × 10⁸/6.55 × 10-⁷

f = 4.58 × 10¹⁴Hz

b) E = hc/wavelength

E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷

E = 3.035 × 10-¹⁹J

1ev = 1.6 × 10-¹⁹J

Therefore E = 3.035/1.6 = 1.9eV