In the sample of water, there are 100 atoms of oxygen and 200 atoms of hydrogen. How will the mass of oxygen compare to the mass of hydrogen?

The ratio of the mass of an oxygen atom to the mass of a hydrogen atom is therefore approximately 16:1. If we have 2 atoms of each element, the ratio of their masses is approximately 32:2, which reduces to 16:1—the same ratio.

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.