The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it whereas mass is the amount of matter contained in a body. The SI unit of weight is Newton whereas the SI unit of mass is Kilogram.
No idea about weightless maybe the objects not apparently acted on by gravity.
I'm not that smart but I think it is c I really hope It helps
Amount of charge on the capacitor=q=10⁻³C
Energy stored=4.5x10⁻³ J
potential difference= 9 V
Energy stored= E= 1/2 q V
4.5x10⁻³ =1/2 q (9)
q=10⁻³C
Thus the amount of charge on the capacitor=q=10⁻³C
