Very quick oxidation reactions result in combustion melting fusion fission

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

The crust of earth may a- continets and ocean floors. b-continents only. c-layers of sedimentary rocks and continents. d-all of the above

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d