When an oxygen atom forms an ion, it gains two electrons. What is the electrical charge of the oxygen ion? -2 -1 +1 +2

answer; 60-100; beats per minute

the denominator has a very specific role.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.