When fruits such as apples and pears are cut, the exposed parts begin to turn brown. This is the result
of an oxidation reaction catalyzed by enzymes present in the fruit. Often the browning action can be
prevented or slowed by adding a few drops of lemon
juice to the exposed areas. What is the chemical basis
for this treatment?

2%? i tried finding the exact sorry if it's not 100% correct ; -;

the question isn't complete here so i can't right an answer '_'

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.