The main agenda of such children is to seek attention , they don't want to study and don't let others study . A solution according to me is ignore him don't react to whatever he say it's like when dogs bark let them bark after a while he himself will realise that what he is doing is a waste of time .if the situation worsens then take a strict action against that child draft a letter to the concerned teacher so that she makes him sit somewhere else , but I think if u make him understand ur point in a sweet manner he will surely understand it . Hope it helps u !! Plzzz mark it as the best :)