Air takes up space in a object that is why wan you posh down a gles in a bucked the air try to push the gles up.
Air has mass use a stick put strange theta are hanging at the end of both tips and use two balloons and full one ballgown with air and one side will be unequal.
Air can exert a force here try this heat water in tin can and put the cap one or it wont work and put it endear running water and i will explain what happend with the water wan you heated it the molecules get's exsided and gose faster and whan the water whorms down the molecules slow down
Air can be compressed. Wan you inflated a object and and it is small add more air the air is gating compressed and the object gets harder wan you add more air