1the total energy is PE+KE. here the total energy is zero implies that K. E is zero as Ankit says, because PE can be assigned to a system and not a particle (eg. gravitational PE exists if there is a gravitational field which is caused by the presence of mass somewhere else and potential energy is given the to the system- particle+mass...... same with electric)
so, i think linear momentum is zero as its velocity is zero
