Forces are pushes and pulls that may change the motion of an object. Balanced forces result in an object remaining at rest or moving at a constant speed. Unbalanced forces result in the acceleration of an object. An object's motion depends on how it changes position.
A - its condensation and gas particles have a higher kinetic energy
a metal with a large number of free-flowing electrons most likely have good conductivity
Alpha particle has a mass of 4 (Two protons and two neutrons)
Neutron has a mass of 1
Beta particle has a mass of about 0 (Electron)
Proton has a mass of 1
So the answer is (2) Beta particle