Calculate the number of photons having a wavelength of 12.0 μm required to produce 1.0 kj of energy.

N = 603.32 × 10 ²⁰

Explanation:

Given data:

Wavelength of photon = 12.0 μm or 12 × 10 ⁻⁶ m

Energy = 1.0 KJ  or 1000 j

Number of photons = ?

Solution:

Formula:

E  = n . h . f

E = energy

N = number of photons

h = planck's constant

f = frequency

it is known that

f = c/λ

thus,

E = N . h . c / λ

Now we will put the values in formula.

1000 j = ( N. 6.63 × 10 ⁻³⁴ j.s × 3 × 10⁸ m/s ) / 12 × 10 ⁻⁶ m

N = 1000 j ×12 × 10 ⁻⁶ m  / 6.63 × 10 ⁻³⁴ j.s × 3 × 10⁸ m/s

N = 12000 j × 10 ⁻⁶ m / 19.89 × 10 ⁻²⁶ j. m

N = 603.32 × 10 ²⁰