What factors that affect ionization energy? a. group number, atomic mass, electron configuration, density c. weight, state at room temperature, density and ionic radius b. only the charge matters d. charge, atomic radius, orbital penetration, and electron pairing

Size of an atom,The effective nuclear charge,Shielding effect,Penetration effect and electronic configuration of an atom.

I'm not sure which of yours is correct but i hope this helps.

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.