Give reason :

The motion of spring is considered as an oscillatory periodic motion

It follows the definition of oscillatory motion

Explanation:

The oscillatory motion is the motion between two fixed points in a fixed interval of time . In this case the spring moves up and down or it can move in left to right in fixed interval of time . That is why , it is called the periodic motion , because it is repeated after fixed interval of time .

connect the batteries in series and hope