Im sorry about my answer a while ago.
answer: it will not be half empty ever. because any gas take all the space of the tank. molecules are everywhere they take so much space.
Gravitational Pull, is the answer. just like we orbit the sun, the moon orbits us. we act almost like a magnet, we follow the biggest guy as leader. if the sun dissapeared, we would die, but probably, we would start to revolve around jupiter as it is the biggest
Pacticles of gas are more compact, but still have the ability to move.
Between atoms (one metall and one non metall) form an ionic bond(NaCl)
