PLEASE ANSWER SOON 1. Explain Phenomena Fill in the blanks to
complete the sentences.
Some buildings are made of limestone, which
is primarily calcium carbonate, a
Over time,
rain reacts with the
carbonate and the buildings are damaged.

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.