Energy of Photon emitted by heated lithium atom E = 2.961 Ă— 10â’19 J
We need energy for only one mole of photons n = 1
Total photons in one mole = 6.022x10^23 photons / mole
Total Energy = n x h x E => 1 x 6.022x10^23 x 2.961 Ă— 10^â’19
Total Energy = 1.783x10^5 J