Consider the reaction
<span>2Al(OH)3(s)→Al2O3(s)+3H2O(l) </span>
<span>with enthalpy of reaction </span>
<span>ΔHrxn∘=21.0kJ/mol </span>
<span>What is the enthalpy of formation of Al2O3(s)? </span>
<span>Substance ΔHf∘ (kJ/mol) </span>
<span>HCl(g) −92.0 </span>
<span>Al(OH)3(s) −1277.0 </span>
<span>H2O(l) −285.8 </span>
<span>AlCl3(s) −705.6 </span>
<span>H2O(g) −241.8</span>
C protons and neutrons, electrons surround the nucleus of an atom in outer shells
The answer is: <span>Sodium (Na) is very reactive because it does not have a full valence shell. Hope this helps :)
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