IB Chemistry S1.3 Notes

In Topic S1.3, HL students need to be able to quantify the energy changes electrons undergo when they absorb or emit electromagnetic waves. Remember that from the electromagnetic spectrum that wave energy is proportional to its frequency (f). The formula for this is:

$E = hf$

In this, h is the Planck constant and equal to 6.63 x 10^-34 Js. An alternative formula can be formed by substituting in the wavespeed equation.

$c = fλ$

$\frac{c}{λ} = f$

$E = \frac{hc}{λ}$