Question

1.What is the wavelength of light. Given energy = 2.91 × 10-19], h = 6.36 × 10-34 Js, c = 3.0 × 108 m/s? 656nm 6.56 nm 0.656 nm 65.6 nm​

Answer 1

we have to find the wavelength of light.

solution : energy of light, E = 2.91 × 10⁻¹⁹ J

plank's constant , h = 6.36 × 10⁻³⁴ Js

we know from Plank's quantum theory, energy of one photon, E = hc/λ

here, c = speed of light = 3 × 10⁸ m/s

⇒ 2.91 × 10⁻¹⁹ J = (6.36 × 10⁻³⁴ Js × 3 × 10⁸ m/s)/λ

⇒ λ = (6.36 × 3)/(2.91) × 10⁻⁷ = 6.5567 × 10⁻⁷ m

= 655.67 nm ≈ 656 nm

therefore the wavelength of light is 656 nm.

Answer 2

Answer:

656 nm

Explanation: