Answer:

because our stomach is not protected by any bone

Explanation:

our heart is protected inside ribcage and hence when someone hit on your chest....it doesn't hurt that much

Verified answer

Answer:

The internal organs like intestines, stomach in the abdomen don't have any bones surrounding them. Hence it pains when someone hits you stomach.

while the internal organs in the chest cavity are protected by the rib cage. Hence it does not pain so much.