This is because oxygen (2.8.6) requires two electrons on its valence shell to attain stable configuration (2.8.8). Hydrogen (1) on the other hand requires one electron on its valence shell to attain stable configuration (2). Therefore in a covalent bond, it requires two hydrogen and one oxygen to share electrons and achieve stable configuration.
Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Answer:
of the reaction is -6313 kJ/mol
of the reaction is -6312 kJ/mol
Explanation:





Therefore,
of the reaction is -6313 kJ/mol.
The chemical reaction in bomb calorimeter is as follows.




Therefore,
of the reaction is -6312 kJ/mol.