Final answer:
The chest lead that should be placed at the fifth intercostal space at the junction of the left midclavicular line is V5 in electrocardiography.
Step-by-step explanation:
When performing electrocardiography, the chest lead that should be placed at the fifth intercostal space at the junction of the left midclavicular line is V5. This is one of the six electrodes that are placed on the chest in a 12-lead electrocardiogram (ECG), along with four electrodes placed on the limbs. The placement of V5 allows for the recording of the electrical signals of the heart from that specific position on the chest.