How to make only one ball bounce?

I want to make it so, that when i touch a ball it jumps up, but now when i touch a ball all of them jump. I'm really tired so i'm really sorry if i don't make any sense. But anyways here's my code. Hopefully someone can fix it :) This is also my first post ever on unity. So pardon my noobness.

 public Vector2 jumpForce = new Vector2(0, 300);

 void Update () {
     Vector3 pos = Camera.main.ScreenToWorldPoint (Input.mousePosition);
     RaycastHit2D hit = Physics2D.Raycast(pos, Vector2.zero);
     if (hit != null && hit.collider != null) {
         Debug.Log ("BOUNCE "+hit.collider.name);
         rigidbody2D.velocity = Vector2.zero;
         rigidbody2D.AddForce(jumpForce);
     }
 
 }

}