Question

1. what is the “vital substance” in the air that priestly was studying? use “modern” biology to explain how you know this.

Explanation:

Priestly was studying oxygen. In modern biology, we know that oxygen is essential for aerobic respiration in cells. During aerobic respiration, cells use oxygen to break down glucose and release energy. This process is fundamental for the survival and functioning of most living organisms.

Answer:

Oxygen.