We're do volcanoes usually form please help me A within 10 miles of the ocean B between earths mantle and core C at fault lines between tectonic plates D within the boundaries of the U. S.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex

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.