PPP
3 As a coral scientist, you have recently been sent a core sample from the Great Barrier Reef in
Australia. Comparing the oldest portion of the coral sample with the newest, you discover that
the oldest pieces of coral contain only 60% of the "C contained in the modern sample. Using that
information, estimate how old this portion of the reef is and discuss your reasoning.

this would be a math

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.