No volcanoes are formed by tectonic plates down below the ground
<span>Answer:
Enthalpy Change = (6 x -393.5) + (7 x -285.8) - (-204.6) + (19/2) 0.....???
like.. (6 x Enth CO2) + ( 7 x Enth H2O) - (Enth C6H14) + (19/2) Enth O2</span>
Chemical changes is all that which occurs with the formation of new substances.
Physical changes are all the transformations of matter without altering its chemical composition occurs. Is any phenomenon that occurs without the formation of new substances.
hope this helps!