In an experiment, four balloons were filled with different gases in order to test which would stay inflated the longest. The gases used were Helium (He), Carbon dioxide (CO2) Oxygen (O2) and Methane (CH4). Rank the balloons in the order they would deflate (effuse) fastest to slowest.

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.