Where are the electrons most probably located in a molecular bonding orbital?
a. in stationary positions between the two atomic nuclei
b. between the two atomic nuclei
c. in circular orbits around each nucleus
d. anywhere in the orbital

C. in circular orbits around each nucleus

Explanation:

In covalent molecular bonding, the electrons that are involved in bonding are shared by the two bonding atoms. This means the electrons are probably located between the two nuclei of the atoms. This is represented diagrammatically by drawing orbitals between the two nuclei. 

For example, Chlorine has 7 electrons in its outermost shell. So Chlorine atom shared one of its electron with other Chlorine atom to complete their octet and it is represented by diagram in the attachment.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

the answer is 75.0%.