Final answer:
The leads placed on the frontal plane in a standard 12-lead ECG are I, II, III, aVR, aVL, and aVF. The leads on the transverse plane are the precordial leads V1, V2, V3, V4, V5, and V6.
Step-by-step explanation:
The standard 12-lead ECG provides a comprehensive view of the heart's electrical activity by placing electrodes on both the frontal and transverse planes of the body. On the frontal plane, limb leads are positioned: these include leads I, II, and III (bipolar leads), and leads aVR, aVL, and aVF (augmented unipolar leads). On the transverse plane, chest leads known as precordial leads are used: these are V1, V2, V3, V4, V5, and V6. The placement of these leads strategically around the body allows for the detection of subtle changes in the heart's function and can reveal conditions such as regions of damaged tissue known as infarcts.