In what condition do acceleration and deaccelration

Im not sure what are you asking about. But in physic/ mechanic usually when the object against gravity, its deceleration but when the object follow the gravity its acceleration

Also usually when the object move to the left side the speed will be negative (-) this is probably because of deceleration? since deceleration = -acceleration.

iron would move it is magnetic there is a mag field around the current in the wire

explanation:

considering the bohr theory, the type of connection that requires the transfer the answer conuldn't be right