Arthropods, like spiders and lobster, don't have blood like mammals do; instead, they have

Arthropods like spiders do not have blood like animals, rather they have a fluid called hemolymph  in their circulatory system. Hemolymph is found in the circulatory system of arachnids, crustaceans and insects. Molluscs too have a circulatory fluid akin to this type.

In insects, exchange of oxygen and carbon dioxide occurs in  a tracheal system which means they respire directly through their body surfaces. So the circulatory system transports nutrients but only a small portion of oxygen. 

In both insects and other arthropods as well as molluscs, hemolymph contains hemocyanin, a copper based oxygen transport molecule. 

this is a good question! i'll do some research and come back when i have the answer!

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.