Is aluminum a stable element

Based on its chemical properties, identify the position of each chemical family on the periodic table.

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.

The chemical formula for emerald is be3al2(sio3)6.an emerald can be decided as