In what ways is the compound formed of iron and oxyge. different from a mixture of iron and oxygen

This can be explained by determining the difference between a compound and a mixture. In a compound, the elements are chemically combined meaning that they are sharing chemical bonds and therefore can only be chemically separated through a reaction. The elements in the mixture are only physically mixed and do not share chemical bonds. The elements can, therefore, be physically separated without a  reaction.  

i believe it is c.) 1575 j.

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.