Why can alloys not be described using chemical formulas?
a) alloys are mixtures with undefined proportions
b) alloys are mixtures instead of compounds
c) alloys have a network structure called a crystal lattice
d) alloys have a structure that lacks covalent bonds

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.