Final answer:
The statement is true; hyperventilation results in lower levels of PCO2 and H+, leading to a condition known as respiratory alkalosis.
Step-by-step explanation:
The statement that when a person hyperventilates, there are lower than normal levels of PCO2 and hydrogen ion in arterial blood, a condition called respiratory alkalosis, is true. Hyperventilation is the condition where there is an increased ventilation rate that leads to abnormally low blood levels of carbon dioxide (CO2) and a higher (more alkaline) blood pH. The elevated respiratory rate can be triggered by various factors, including anxiety, fever, or an aspirin overdose. These events cause a deficiency in carbonic acid concentrations due to the excessive CO2 being exhaled, thus leading to an alkaline state known as respiratory alkalosis. As a result, the normal concentration of hydrogen ions (H+) in the blood is reduced, contributing to an increase in pH and creating an alkaline environment.