The law of mass action suggests that

The law of mass action suggests that the rate of a chemical reaction is directly proportional to the product of the masses of the reactants. In this, each mass is raised to a power, which is equivalent to the coefficient of that reactant in the chemical reaction.

For example- For the chemical reaction-

aA + bB → C + D

Rate of the reaction α [A]ᵃ [b]ᵇ

Rate of the reaction = k [A]ᵃ [b]ᵇ

where, k = rate constant

a+b = order of the reaction.

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.