Ionic Bond formation

[Leslie Contreras 1D]

when you add the electron to Calcium the energy required is 494
where is that number found?
what constitutes as required a cation needing to push an electron or is that released because of the electron leaves?

[Susu Le 1F]

That energy is required to overcome the effective nuclear charge that is acting on the electron.

[Leslie Contreras 1D]

That energy is required to overcome the effective nuclear charge that is acting on the electron.

SORRY I still do not understand

[SammiOrsini_1B]

if the energy required is 494 would we be expected to find this number or is the number given? I have no idea how to find that number

[Paywand Baghal]

if the energy required is 494 would we be expected to find this number or is the number given? I have no idea how to find that number

it should be given, but I believe we just need to know the topic and be able to use any information given, not to memorize.

[Chem_Mod]

If you are referring to the ionization energy of Na, this energy must be added to the atom to separate the electron from the rest of the atom:

Na + 494 kJ/mol --> Na⁺ + e^-

The ionization energy is usually measured experimentally.