What is this weed?

There is a weed that grows around my area that fascinates me. It blooms a small yellow flower in the early summer. In the late summer, the blooms close and form a seed pod about 1cm in length, positioned vertically, and shaped sort of like a skinny bullet. These seed pods, when touched, shoot tiny black seeds about the size of poppy seeds out. The leaves on this plant are perfect heart shapes and are about the size of clover leaves.

Anyone recognize this description and know what this is? I’d love to read more about it. I could probably find a patch around my yard and post a picture tomorrow, if need be.