Question

a ballon when kept in sun bursts after some time why

Answer 1

A balloon when kept in sun bursts after some time because outside the temperature is high and due to that the kinetic energy increases and the molecules of gas particles inside exerts a pressure on the walls of the balloon so it will continue to expand and there a stage will come that the balloon will burst..

Answer 2

temperature is directly proportional to pressure. as temperature increases pressure also increases. the temperature of air inside the balloon kept in sun increases hence pressure also increases and the balloon bursts.