I've been searching for the answer all over the internet, and all I found is two different answers and I need to know what answer is right.
$E=nhf$ is an equation to find the 'total energy' for a group of photons in the same frequency; for a single photon $E= hf$, is often expressed as $E= h\nu$; $n$ being the total number of photons. Because photons tend to travel in large groups, be better using this one: $$E = n\cdot N_A \cdot h\cdot f$$ In this equation $n$ is the number of moles, and $N_A$ is Avogadros number.
The $n$ refers to the nth state of vibration, $f$ is the frequency of the lowest energy state, $h$ is a constant called the Planck constant, and $E_n$ is the energy of the $n-$th level of vibration.
So who's right?