Final answer:
Ventricular repolarization on the EKG is represented by the T wave, while atrial repolarization is not visible as it is masked by the QRS complex.
Step-by-step explanation:
On the EKG, ventricular repolarization is represented by the T wave. The EKG features several prominent points: the P wave, the QRS complex, and the T wave. The P wave indicates atrial depolarization, the large QRS complex signifies the depolarization of the ventricles, and the T wave represents ventricular repolarization. Atrial repolarization is masked by the ventricular depolarization and occurs during the QRS complex, which means it is not visibly represented on an EKG.