Question

describe a simple activity to prove that object of density less than that of the liquid floats on it

Answer 1

when a cork is immersed in water it floats whereas a iron nail nail sinks . thus, objects having density less than that of the liquid float in it and objects having more density than that of the liquid sink

Answer 2

let take an example if you throw a plastic ball in water it will float because it has lower density than water . this happen because water also exert a upward force called boyunt force or byouncy which applying force on upward direction . if the plastic ball was higher denser than water so the byount force is less and it sink in water otherwise it float in water .
hope you understand ..