In the box provided explain why living organisms contain more hydrogen atoms than any other atoms, yet 65% of a typical organism’s mass is oxygen.

i believe the answer would be b. hope it : )

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.

instead of copying and pasting things off of tests or work done on computer which im sure you did, try and read over the question carefully