Calculate the energy of a photon with wavelength λ = 0.21 m.

E = hν = hc/λ = 6.6 × 10⁻³⁴ × 3 × 10⁸ / 0.21 = 0.94 × 10⁻²⁴ J
E = hν = hc/λ = 6.6 × 10⁻³⁴ × 3 × 10⁸ / 0.21 = 0.21 × 10⁻²⁴ J
E = hν = hc/λ = 6.6 × 10⁻³⁴ × 3 × 10⁸ / 0.21 = 1.21 × 10⁻²⁴ J
E = hν = hc/λ = 6.6 × 10⁻³⁴ × 3 × 10⁸ / 0.21 = 0.94 × 10⁻²³ J

Correct answer: E = hν = hc/λ = 6.6 × 10⁻³⁴ × 3 × 10⁸ / 0.21 = 0.94 × 10⁻²³ J

Solution

The energy of a photon is calculated using the formula E = hc/λ. Substituting h = 6.6 × 10⁻³⁴ J·s, c = 3 × 10⁸ m/s, and λ = 0.21 m, we get E = (6.6 × 10⁻³⁴ × 3 × 10⁸) / 0.21 = 0.94 × 10⁻²³ J.

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