We’re being asked **how many kj** are being emitted by a **1 mole red light **with **725 nm** of wavelength.

Recall that the ** energy of a photon (E)** is given by:

$\overline{){\mathbf{E}}{\mathbf{=}}{\mathbf{hv}}}\left(1\right)$

where:

**h** = Planck’s constant (6.626 × 10^{–34} J • s)

**v** = frequency (in s^{–1})

Also, recall that the frequency (v) and wavelength (λ) are related:

$\overline{){\mathbf{\lambda}}{\mathbf{=}}\frac{\mathbf{c}}{\mathbf{v}}}\left(2\right)$

where:

**c** = speed of light (3.0 × 10^{8} m/s)

A mole of red photons of wavelength 725 nm has kj of _____.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the The Particle Nature of Light concept. You can view video lessons to learn The Particle Nature of Light. Or if you need more The Particle Nature of Light practice, you can also practice The Particle Nature of Light practice problems.