 
 <prompt> ```Planck constant na wetin again? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context:``` <response>: Classical statistical mechanics need h to dey exist (but e no define im value). Finally, afta Planck discover, dem come sabi say physical action no fit get any kain value wey e like. Instead, e must be some multiple of one very small quantity, wey dem dey call "quantum of action", wey dem dey call Planck constant now. Classical physics no fit explain dis fact. For many cases, like for monochromatic light or for atoms, dis quantum of action also mean say only certain energy levels dey allowed, and values wey dey in between dey forbidden. 