During chest compressions on a child, a rescuer should place hands over which specific part?

The correct answer is the lower half of the breastbone. When performing chest compressions on a child, the rescuer must ensure that the compressions are delivered to the appropriate area to be most effective. The placement over the lower half of the breastbone allows for maximum compression of the heart, which is located slightly more centrally in the chest cavity, just behind the sternum. Properly positioned compressions on the lower half of the breastbone help in effectively pumping the heart to circulate blood during a cardiac arrest situation. This alignment is crucial because it ensures that the force applied during compressions directly impacts the heart.

Using the upper half of the breastbone would not be effective, as it may not provide adequate compression of the heart. Similarly, compressing the side of the ribcage or the upper abdomen would not compress the heart effectively and could risk causing injury to the lungs or organs rather than aiding in circulation. Thus, correct hand placement is vital for effective and safe resuscitation efforts.